Okay, here is what i do. Really, i might do this for a week and then i dont set them agian until maybe day or two before the show. I dont practice it everyday as i dont want them to get sick of working their neck and body for me, so teach them how (they wont forget) and then let it go until a day or two pre show and i go back over it agian.
I work from the back of the horse to the front. Hint: when you set the back legs dont step them back and then set their legs, when you back them up and set them it normally makes them look sickle hocked, always step them back up agian to set. Anyway, i gentle poke their chest and put pressure on the noseband of the halter until i get their feet set as i went them in the back (dont worry about the front yet), practice this and then when you touch their chest, they will set their back feet automatically.
Then, i ask them to set their front feet. I show them a bit of grain (or just my hand) and give a gentle yank on the halter and ask them to step up a step wth their front feet, IF and AS SOON as they move a hind foot BACK them up about 10 steps (i normally give a few good yanks on the lead too), walk them back up and start over agian. Set the back feet, then show your hand or grain and ask them to step up with the front feet ONLY, if they step up with the back feet back them up another 10 feet agian. They will learn that if they move their back feet that they will get "punished". It works for me, really ..normally after about 10 minutes they understand this, but i will do it normally about 3-5 days. Its a simple concept for the horses
.
Oh, and once they learn to step up when you ask them to with the front feet, after you get ALL their feet set, i normally give a gentle yank on the lead to say "Stay" and now show your neck. If they step up when im infront of them and baiting them, then i yank the lead. Sounds confusing but really its not
.