Some tips & tricks that I've learned:
- Join a squad and play with the squad members. Spawn on them, run around with them etc. You'll learn pretty fast this way.
- Reload.
- Stick to walls/cover. If you're in the open you won't live too long.
- Spot enemies. When you see an enemy, press Q to spot him. This helps you and your team immensely. You can also spot vehicles this way.
- Reload.
- Drop Health/Ammo a lot. You help your team out and you get points.
- If you're a medic you'll see lightning bolts on your map and above dead players. You can use the defibrillators to revive these players. The defribs are below the medic supply in your weapons list.
- Keep moving.
To use the health and ammo supplies, you need to choose Assault or Medic at the load out screen. Once you spawn, scroll through your weapons until you hit the health/ammo box, click to drop it!
Unfortunately there is not much you can do about snipers. Just don't hang around in one spot too long. If you need to go over some open land, know where you need to be and SPRINT like hell till you reach cover.
Oh and reload!!
see you on the battlefield