If the other team cant see you yet have an extra mask of the same type as the other one. When they see the mask out they might shoot it while they are lookin the other way you shoot them up. I did this its so funny that it works so good.
You can also spread out alot and dont have a pattern.. In this diagram youll see what I mean
Y= Yer team
T= Ther team Y
Y Y | Y
=== == ===
=== == ========
T T T T
See the Y all the way to the right. He can always see the T all the way to the left. He would have to move. Its a win win situation. If he stays he's hit and if he moves he will probably get hit.
If possible try to tuck your elbows in so that they are behind the bunker. That way all they can see is your face and the gun..