I'm a 'psycho fighter' to quote my friends. I always let them hit me first, then when I've peeled myself off of the floor, lay into the bastard. Dig your thumbs into his eyes, biting off a chunk of his face and kneeing him in the balls at the same time. My dad told me that the key to winning a fight is fear, and the key to fear is immense pain. Never NEVER scare them before they are blind, because thats when the chavs pull knives out. O yeah, and after you've done in the first guy, look around for another one, if noone steps up to the mark do that first guy again. I love my dad.
EDIT: Punches and kicks for when they are on the floor, not before!