Infantry:
All:
Quickly enter vehicle
Hold down "E" as a friendly vehicle is coming at you; no matter how fast it's going, you'll be picked up unharmed. Also works while jumping of a building.
Defuse friendly and enemy mines
Engineers can defuse friendly and enemy mines and claymores by crouching over it with the wrench.
AA Tipps
Bombers can spot enemy vehicles and AA stations. So it's not wise to camp so much especially in the AA station since you're an extemely easy target. Hop into them only when you got something to shoot at within range.
Save a dead medic with his kit
Get your fingers familiar with the switch kit key. Default 'G'. I set mine to 'F' since it's a bit easier. It comes in handy if you want to save a medic that's dead. Pick up his hit and save him.
Use surroundings
Certain maps have barrels and tanks on the streets that can be blown up if you shoot at it. Use them to your advantage and be aware of your surroundings so you don't get owned by them.
Detonate dead allies C4
If you see a friendly spec ops attempting to c4 a tank, but gets killed up before he can press the detonator, run over and pick up his kit. You can then press the detonator to blow up the tank yourself. Really important if theres no other AT or spec ops around.
Revive you SL
If your squad leader is a medic and gets killed, pick up his kit and use it to revive him. Hell, if he gets killed and isn't a medic, look around for other medic kits to pick up and use to revive him.
Firing modes
Hit 3 to switch between firing modes, depending on your weapon/kit you can choose Full auto, 3 shot burst and single fire. This can make HUGE difference in accuracy.
Slide down ladders
Pressing the sprint button while going down ladders will make you slide down the ladder. Quick way to get down without risking health jumping down. Also you can change to different camera views for some reason on the ladder.
Sniper:
with in 100m (untested at longer range) take one shot with the sniper rifle then quickly take out the pistol and take one shot its a kill, almost every time.
Stay in zoomed
Keep holding the fire button down after taking a sniper shot, you will be able to see where the bullet lands and adjust.
Avoid skylining
Avoid skylining your self on ridges. If you have sniper shots incoming the first place you look is towards any high ground and if you see a smooth green ridgeline against the blue sky and there is a supicious bump in the middle you are going to start shooting back.
Engineer:
When mining remember that any flag you are defending your army may soon be attacking and that entrances are also exits, don't mine friendly bases closed.
Shotgun rocks
People highly underesmate the shot gun it can take out people from 40 yards away with 3 or 4 shots
Watch out whist repairing
Remember that whist repairing friendly vehicles it is not so smart to be running up behind a friendly tank with your wrench out. It’s a sure way to get backed over.
Spec. Ops.:
Hide and stick C4
If you wanna hide C4 at a base, just throw it into the cement block that holds the flag up and it'll disappear. Also remember that you can stick C4 to everything, including infantery soldiers.
Blowing up artillery with less c4.
On certain maps, like Golf of Oman, you can blow up artillery with less c4 if you place it between the artillery guns, instead of on them.
Antitank:
Guide you AT-missiles
Keep holding the fire button down after shooting the anti-tank missle, you'll be able to guide it. Or you can aim above or beside your target. Then fire and wait until the missile gets close before putting the reticle over the target. That way, the target doesn't get a missle warning until a split second before your missle hits. Works great at long range.
Do more damage
When behind a tank shoot the treads not the chassis. It takes them out faster, can be the difference between life and death.
Tanks and APCs:
Better view whilst guarding/capping flags
If you are in a tank or APC in an urban area guarding a flag or trying to cap it allways stay in external view. This way you can see if any sneaky sneaky Spec Ops are trying to set C4 on your tank, or if any Eng. are trying to plant mines around you. Make sure you can swich to internal view quickly when spotting someone.
Shooting the Cannon
Shooting the cannon on ground units is the same learning curve as using the grenade launcher since it also has a drop (not as bad as the grenade launder though). It just takes little time to learn and you will get the feel for it. Shooting at helos is a little more tuff since the gravitational force shooting at a higher angle is alot more stressful on the cannon. Whichever the way the helo is flying shoot far more ahead of it depending on how fast its going. You'll be amazed on how much lag time there is shooting the cannon upwards then you do shooting it horizontally. This too you can overcome with a little practice and when you do you will be a menace to helos.
Be an Engineer when tanking
When coupled it can be the deadliest thing on the field. When your armor bar goes a lower then half bar, reverse and find a safe spot to repair then head back into combat. You get massive kill points and massive Engineer points and you will be suprised on how much repairing you will be doing to other vehicles you pass by.
Flag capturing
Instead of going in and capturing a flag, stay far away and shoot your cannon on spawning players until your teammates start to go in. It helps keep the enemies low for your teammates to go in. When you see any of your teammates capturing the flag, move in and give him protection and support. Your range is your advantage against infantry.
Against other tanks
shoot and move. A moving target is harder to aim at. As a tanker, always find corners of buildings to shoot from. After you shoot you can easily reverse and get cover. Use your smoke when you have low armor left and find a safe place to repair.
Try to get a secondary gunner
Suprisingly Anti-tankers are not your worst enemy, Spec Ops are. You will get killed mostly from this class since they can insta-kill you and they tend to be sneaky and always come from behind. Have you support gunner look out for these people since your view is limited to where your barrel faces.
Against Helos
When you see a helo coming straight at you, either start moving to to side, or move towards him. Staying at the line of his barrage of missles is not the smart thing to do. Moving to the side will make it hard on the helo to change directions and moving towards him will limit his time to get his missles off. After he passes you go back towards him and try to stay below him limiting his view and shoot the belly of the helo. He will turn back around and relize you're not there.
Against Jets
another one of your worst enemies: they usually are too fast to even notice one coming but if you do try to stay out of his line of attack and do the best to shoot him.
Smoking
Remeber, tanks and APC's can blow smoke by pushing X. This is great for flag assaults as it gives your grunts some cover.
Swiching seats
When you're alone in an APC don't limit yourself to the driver seat. It has a bunch of seats with guns you can use. So remember them and you can shoot those c4 monkeys in the face before they get a chance to blow you up. Learn to swich between ths seats fast.
Self-healing-gunner
If you have a friend for a gunner, have them go medic. That way they can duck down and heal them selfs when taking damage.
Planes:
Creep up from behind
For plane dogfighting, switch to bombing mode while chasing down planes. You can sneak behind them then switch to missles when you're lined up and surprise them snice the wont get the alarm while you are in bombmode.
Watch your bombs land
When doing bomb runs hit the external camera to get the nose back view, this way you can spot where your bombs land.
MG Power
If you are behind another plane that is flying steady and doesn't know about you. Make sure you have the bombing sight, don't switch over, just tear him up with the machineguns, the MG's are VERY good against other air assets and he wont even notice until hes dead.
Identify Stingers
When flying into a base, switch to bombing mode. If there's someone in the stingers, a box will pop up around them.
Helos:
Repair with supply crates
Helicopters can be repaired using the supply crates. So get your commander to set one up in a good spot so you don't always have to fly back to the pad to repair/resupply
Repair on enemy aribase
Once you capture an enemy air base, you can use their runway and helipads to repair and to get ammo.
Look around
Before taking off in a chopper, look around in mouse-look mode by holding the CTRL key.
Capping in a Blackhawk
When flying the blackhawk, make sure you are the squad leader and fly it HIGH. Hover over a cap point and your team mates can spawn in on you and parachute out.
Commander:
Repair assets with supply crates
As commander you have the option of repairing the artillery (if they are close together) by dropping a supply crate.
Hide!
Find a hiding spot and stay there and focus all your attention to the comander controls. You may not get as many kills or points but it really helps your team. Look for commanding spots which are only accesible by helocopter.
Reapir your own assets
Commanders benefit from using the engineer kit as it allows for them to easily repair the arty, uav, and radar without wasting a supply drop or calling an engineer out from a squad.
Other tipps:
All english, all the time
Tired of not understanding the incoming artillery warnings as MEC or China? Set "English VO Only" under Options->Audio->Language
Increase FoV in the air
Hitting F9 (cockpit view) will remove the model of your plane/heli. This greatly increases the FoV.
Get down mountains fast and safe - In vehicle
On maps with cliffs, use the vehicle to slide/drop down the declines to get to lower roads quicker. If down right your vehicle will take no or almost no damage and you save loads of time. Also if there is a body of water an APC will take no damage and requires little skill to do.
Get down mountains fast and safe - On foot
When you are on foot You can get yourself down a mountain with many odd angles with minimal loss of health by spamming jump and 9 -buttons as soon as your feet touch the ground. Pressing jump while on a diagonal slant will actually push you away from the face of the mountain that could avoid other odd protrusions. The best place to practice this is Songhua Stalemate map by the American most rearward base.
All:
Quickly enter vehicle
Hold down "E" as a friendly vehicle is coming at you; no matter how fast it's going, you'll be picked up unharmed. Also works while jumping of a building.
Defuse friendly and enemy mines
Engineers can defuse friendly and enemy mines and claymores by crouching over it with the wrench.
AA Tipps
Bombers can spot enemy vehicles and AA stations. So it's not wise to camp so much especially in the AA station since you're an extemely easy target. Hop into them only when you got something to shoot at within range.
Save a dead medic with his kit
Get your fingers familiar with the switch kit key. Default 'G'. I set mine to 'F' since it's a bit easier. It comes in handy if you want to save a medic that's dead. Pick up his hit and save him.
Use surroundings
Certain maps have barrels and tanks on the streets that can be blown up if you shoot at it. Use them to your advantage and be aware of your surroundings so you don't get owned by them.
Detonate dead allies C4
If you see a friendly spec ops attempting to c4 a tank, but gets killed up before he can press the detonator, run over and pick up his kit. You can then press the detonator to blow up the tank yourself. Really important if theres no other AT or spec ops around.
Revive you SL
If your squad leader is a medic and gets killed, pick up his kit and use it to revive him. Hell, if he gets killed and isn't a medic, look around for other medic kits to pick up and use to revive him.
Firing modes
Hit 3 to switch between firing modes, depending on your weapon/kit you can choose Full auto, 3 shot burst and single fire. This can make HUGE difference in accuracy.
Slide down ladders
Pressing the sprint button while going down ladders will make you slide down the ladder. Quick way to get down without risking health jumping down. Also you can change to different camera views for some reason on the ladder.
Sniper:
with in 100m (untested at longer range) take one shot with the sniper rifle then quickly take out the pistol and take one shot its a kill, almost every time.
Stay in zoomed
Keep holding the fire button down after taking a sniper shot, you will be able to see where the bullet lands and adjust.
Avoid skylining
Avoid skylining your self on ridges. If you have sniper shots incoming the first place you look is towards any high ground and if you see a smooth green ridgeline against the blue sky and there is a supicious bump in the middle you are going to start shooting back.
Engineer:
When mining remember that any flag you are defending your army may soon be attacking and that entrances are also exits, don't mine friendly bases closed.
Shotgun rocks
People highly underesmate the shot gun it can take out people from 40 yards away with 3 or 4 shots
Watch out whist repairing
Remember that whist repairing friendly vehicles it is not so smart to be running up behind a friendly tank with your wrench out. It’s a sure way to get backed over.
Spec. Ops.:
Hide and stick C4
If you wanna hide C4 at a base, just throw it into the cement block that holds the flag up and it'll disappear. Also remember that you can stick C4 to everything, including infantery soldiers.
Blowing up artillery with less c4.
On certain maps, like Golf of Oman, you can blow up artillery with less c4 if you place it between the artillery guns, instead of on them.
Antitank:
Guide you AT-missiles
Keep holding the fire button down after shooting the anti-tank missle, you'll be able to guide it. Or you can aim above or beside your target. Then fire and wait until the missile gets close before putting the reticle over the target. That way, the target doesn't get a missle warning until a split second before your missle hits. Works great at long range.
Do more damage
When behind a tank shoot the treads not the chassis. It takes them out faster, can be the difference between life and death.
Tanks and APCs:
Better view whilst guarding/capping flags
If you are in a tank or APC in an urban area guarding a flag or trying to cap it allways stay in external view. This way you can see if any sneaky sneaky Spec Ops are trying to set C4 on your tank, or if any Eng. are trying to plant mines around you. Make sure you can swich to internal view quickly when spotting someone.
Shooting the Cannon
Shooting the cannon on ground units is the same learning curve as using the grenade launcher since it also has a drop (not as bad as the grenade launder though). It just takes little time to learn and you will get the feel for it. Shooting at helos is a little more tuff since the gravitational force shooting at a higher angle is alot more stressful on the cannon. Whichever the way the helo is flying shoot far more ahead of it depending on how fast its going. You'll be amazed on how much lag time there is shooting the cannon upwards then you do shooting it horizontally. This too you can overcome with a little practice and when you do you will be a menace to helos.
Be an Engineer when tanking
When coupled it can be the deadliest thing on the field. When your armor bar goes a lower then half bar, reverse and find a safe spot to repair then head back into combat. You get massive kill points and massive Engineer points and you will be suprised on how much repairing you will be doing to other vehicles you pass by.
Flag capturing
Instead of going in and capturing a flag, stay far away and shoot your cannon on spawning players until your teammates start to go in. It helps keep the enemies low for your teammates to go in. When you see any of your teammates capturing the flag, move in and give him protection and support. Your range is your advantage against infantry.
Against other tanks
shoot and move. A moving target is harder to aim at. As a tanker, always find corners of buildings to shoot from. After you shoot you can easily reverse and get cover. Use your smoke when you have low armor left and find a safe place to repair.
Try to get a secondary gunner
Suprisingly Anti-tankers are not your worst enemy, Spec Ops are. You will get killed mostly from this class since they can insta-kill you and they tend to be sneaky and always come from behind. Have you support gunner look out for these people since your view is limited to where your barrel faces.
Against Helos
When you see a helo coming straight at you, either start moving to to side, or move towards him. Staying at the line of his barrage of missles is not the smart thing to do. Moving to the side will make it hard on the helo to change directions and moving towards him will limit his time to get his missles off. After he passes you go back towards him and try to stay below him limiting his view and shoot the belly of the helo. He will turn back around and relize you're not there.
Against Jets
another one of your worst enemies: they usually are too fast to even notice one coming but if you do try to stay out of his line of attack and do the best to shoot him.
Smoking
Remeber, tanks and APC's can blow smoke by pushing X. This is great for flag assaults as it gives your grunts some cover.
Swiching seats
When you're alone in an APC don't limit yourself to the driver seat. It has a bunch of seats with guns you can use. So remember them and you can shoot those c4 monkeys in the face before they get a chance to blow you up. Learn to swich between ths seats fast.
Self-healing-gunner
If you have a friend for a gunner, have them go medic. That way they can duck down and heal them selfs when taking damage.
Planes:
Creep up from behind
For plane dogfighting, switch to bombing mode while chasing down planes. You can sneak behind them then switch to missles when you're lined up and surprise them snice the wont get the alarm while you are in bombmode.
Watch your bombs land
When doing bomb runs hit the external camera to get the nose back view, this way you can spot where your bombs land.
MG Power
If you are behind another plane that is flying steady and doesn't know about you. Make sure you have the bombing sight, don't switch over, just tear him up with the machineguns, the MG's are VERY good against other air assets and he wont even notice until hes dead.
Identify Stingers
When flying into a base, switch to bombing mode. If there's someone in the stingers, a box will pop up around them.
Helos:
Repair with supply crates
Helicopters can be repaired using the supply crates. So get your commander to set one up in a good spot so you don't always have to fly back to the pad to repair/resupply
Repair on enemy aribase
Once you capture an enemy air base, you can use their runway and helipads to repair and to get ammo.
Look around
Before taking off in a chopper, look around in mouse-look mode by holding the CTRL key.
Capping in a Blackhawk
When flying the blackhawk, make sure you are the squad leader and fly it HIGH. Hover over a cap point and your team mates can spawn in on you and parachute out.
Commander:
Repair assets with supply crates
As commander you have the option of repairing the artillery (if they are close together) by dropping a supply crate.
Hide!
Find a hiding spot and stay there and focus all your attention to the comander controls. You may not get as many kills or points but it really helps your team. Look for commanding spots which are only accesible by helocopter.
Reapir your own assets
Commanders benefit from using the engineer kit as it allows for them to easily repair the arty, uav, and radar without wasting a supply drop or calling an engineer out from a squad.
Other tipps:
All english, all the time
Tired of not understanding the incoming artillery warnings as MEC or China? Set "English VO Only" under Options->Audio->Language
Increase FoV in the air
Hitting F9 (cockpit view) will remove the model of your plane/heli. This greatly increases the FoV.
Get down mountains fast and safe - In vehicle
On maps with cliffs, use the vehicle to slide/drop down the declines to get to lower roads quicker. If down right your vehicle will take no or almost no damage and you save loads of time. Also if there is a body of water an APC will take no damage and requires little skill to do.
Get down mountains fast and safe - On foot
When you are on foot You can get yourself down a mountain with many odd angles with minimal loss of health by spamming jump and 9 -buttons as soon as your feet touch the ground. Pressing jump while on a diagonal slant will actually push you away from the face of the mountain that could avoid other odd protrusions. The best place to practice this is Songhua Stalemate map by the American most rearward base.