Guillotine

Easiest move in the world.  You wrap your arm around someones neck and squeeze.  People are surprisingly willing to let their heads be pulled down, and you can slap a guillotine on in no time.  Another variation of the move is a certain grip you can use.  This grip practically ensures an instant tapout.  Put your left hand out, sideways, palm away from your body.  Now put your right hand straight out and clasp palms.  This should feel incredibly awkward.  Now yes it feels goofy, but your entire forearm is now basically bone into their windpipe.  Really applying this grip in any situation will increase the potency of a choke by several magnitudes.