I've got 11,8,16 in terms of Gold, Silver Bronze. I haven't played commander in a while. Only 15 hours total for that.
Most of my medals comes from playing Medic. I join a good squad that uses VOIP and are constantly talking. Not about crap like what the wather is like or what they had for dinner in ths school cafeteria.
I stick with them and tell them all that I'm a medic and if they get taken out or shot, I'm here to give them med packs or revive them. Most of the time, there isn't a medic on the squad. Having 2 medics on 1 squad is not bad. It keeps the whole squad healthy. If its an issue or there are already 2 medics, I respawn as Support and constantly hand out ammo packs and get the ammo points. It also helps to be squad leader and a medic at the same time. If your squad members are spawning on you, I think you get fractional points that add up.
Not sure, but my best round was when I was a medic and also squad leader. Everyone was spawning on me, cause I hung back and did some sniping froma distance and threw some grenades and stayed alive. Then after the flag would turn neutral I would run out to join them and get the assist point and then heal and revive anyone that needed it. In a firefight, I would stay prone behind a wall near everyone and just revive them if they got taken out. Then I run around a building corner so that if a grenade landed on them, I would not get taken out with them.
Just some tips...