When mugging you can blindside the opponent, dont run down the side run straight to his bunker as if going into it, then go round when you get there, this makes it so he cant see you coming (9 times out of 10) he will probably be shooting out the sides, also if your the last guy left thats where they will mug you from.
My personal fav. is going to the other side of the opponents bunker and standing there while I figure out what side he is firing, then walk round and shoot him, as for shooting in the head etc. I don`t really agree with that, basically the paint is going to burst anywhere at that range and you cant really aim anyway as you are sort of guessing where he is, my tip walk round and fire til you see one burst then carry on, if he shoots you then you should be wiped down.