To prep for show season with my horse(s) I usually don't body clip unless they are really hairy indoor horses. Usually for the coat I just feed a balanced diet and blanket properly and they have a shiny, short winter coat. What I will clip is the legs from the knee/hock down and the head. If a horse is clipper shy or head shy I just take it really slow. With their legs I'll do a bit every day and usually I end up in some strange crouched position to keep their leg up and keep them from twitching or leaping. With the head, it can be really tough with a head shy horse to use clippers, so I will just use scissors. I only cut off the long hairs under their jaw, and do the bridle path. I will also cut some hair out of their ears if is sticks out. Then because I do dressage I'll also clip the top of the tail, I don't braid it for shows.
I'll also put shoes on the horse just because their going to be on unfamiliar footing at shows. And while the farrier is out I'll get her to rasp the hooves so I have an easier time sanding them later. And if the horse has ergots I'll get her to nip those off. And if their chestnuts are really long I'll get those nipped off too. And then I put vaseline on the chestnuts and ergots.
And then all that's left is grooming at the show! For that I bath, clean the white parts of the horse, rinse with water and baby oil, condition the tail and put silicone spray on the white parts. Then I'll braid, sand & polish the feet, groom the body (I use "Miracle Groom" on their body because it doesn't cause anything to slip!), brush out the tail and then oil them.
I'm instense about grooming though... :)
Oh wow, thanks so much. And of course, thanks to everyone else! Everyone has given lots of great info! Mayo? I heared of using that for my own hair, not for a horse! LOL, thanks! I will sure put everyone's info to great use this year!