One skilled sniper was sniping a far away land when I was infront of him, but underneath a rock.

I typed "Look behind you"

He turned.

I ran from the rock and threw 2 knives into his face

ok, 1st i'll throw a incenerary nade in the middle so the 3 of you's guys and usually frightens someone.  ak the first closest guy and by that time the 2nd should be there so i finish his ass off with the shotgun (BALOOOM!.  now that 1st guy that got scared is running away so i follow and throw a knife at his noob ass and it hits him.  so he immediatly turns around and "duh, duh"!  slice to the throat.  ah.

While moving away from them backwards and sideways and changing up so they can't lead you, change your weapon to the knife then go slicing. That has worked often. I also would switch to the loudest weapon and stick it in someone's face and take out as many as I could before dying.

I dig the pulled pin effect too...haha

I drop all my grenades near me but not too close to their blast and whip out my shotgun.