The two glitches thats what i call them because i dont have a real name for them yet except for the second one which is called the barrel roll are used for trickshots.

1.The first glitch is simple but you have to have a pistol with tactical knife on!
You simply have your secondray out and tap sprint for a second then you double tap traingle for PS3. And you double tap Y for Xbox. If you have done it correctly your knife should do some weird stab thing.

2.This is called the Barrel Roll
Its the same as the knife one but you switch from your sniper to your shotgun and you do the sprint double tap thing as soon as the shotgun comes out. The easy way to do it is by using a spas 12 any attachment.

REMEMBER!
I use these glitches when im going for a jump trickshot just before i take of.