I always start with my voice...then I'll stomp the ground or hit the ground with a whip ( only had to do that once or twice) I don't usually have a whip ...then I go to poking then shoving ( ground work type) then...if that doesn't work I'll slap the hiney. A biting horse gets pushed away......actually I don't let my horses get their mouths near me when we are working unless its my idea. Twister has nipped my daughter and he has lost his nuzzeling priveledges because of it, he always gets his head pushed away. Now when he tried to bit Anthony I caught him bare teethed and ready to go for it, and he got smacked in the neck and pushed off....then it was forgotten. He hasn't tried to bite again but then, I don't give him the opportunity either.
If I get a rump swung around to me...I will smack it everytime. I ususally start with a smack like you would slap your own leg..not that hard...then if they don't move I'll get progressively stronger...usually a "move it" command and a slap/strong pat is good enough. My horses have never offered to kick me but if a horsefly or something else gets 'em I don't want to be in range...They have to realize that I don't want that end pointed at me. They are really good about it now.
The folks that had these horses before we got them had a heavy hand and would slap them in the neck to say good boy just about as hard as I smack them to tell them no. It's really hard to say what each of us concider disipline. I smack less than they did. I also don't find the need to do it everyday either. It's just a once in a while thing for me. They listen to voice commands really well. But that's just my situation and horses...sorry so long... * pulls fresh cookies outta the cyber oven*