Turn your in-game music off:: This will allow you to hear not only footsteps but guns reloading and the occasional "enemy spotted" coming from the other team.



Leave the shadows turned on: I can't tell you how many times I have been saved because I could see somebodies shadow from around a corner.



Don't buy gear right away: After each level you earn you will receive free gear and weapon parts in your mailbox. If you do not get these after you level simply log out and back in.



Cook your grenades: By charging your grenade up before you throw it you do not leave your target time to run away from it. (You charge a nade by holding down the throw button but not releasing it. Just let go before it goes off in your hand)



Depots Depots Depots: They are there for a reason, Use them. If your not a fan of the special weapons in them at least keep your health and ammo full.



Proxy mines: Using the depots to refill your ammo you can place 2 of these wonderful toys out at a time, and remember these bad boys don't have to go on the floors all the time. Not many people look for these on the ceiling.



Flamethrowers: The best/fastest way to take out a hardsuit. (and/or groups of people)



Learn your maps: Just because you can see through walls every couple of seconds doesn't mean you should know your way around. If you need to join a room with 1 other person in it and just run around until you get the hang of it.



HRV Blackouts: A good way to not only hide yourself but cover up proxy mines as well.



Doors: If you are a few people short covering an area of the map, shut a few doors. Door control panels are also a good place to hide a proxy mine.



Shields: Not only great for stopping bullets but when placed in a doorway can be really annoying causing people to have to find a longer path. Also great for taking out turrets, Pull the shield in front of you, walk up to the turret, and melee.