Join Date: Dec 2009
Location: Ft. Worth, Texas
If you can, go watch a 4H show in your area. That will give you the best idea of what the "norm" is for where you live. At a bare minimum, the horse should be clean, brushed, feet trimmed, and whiskers and bridle path clipped. To clip the bridle path, start between the ears and clip back to the point where the tip of the horse's ear reaches when you lay it straight back.
The 4H shows around here are very big (20 to 30 in each class) and I am seeing more and more people leaving the manes long and unbanded for shows. However, we do have a lot of riders who show their Halter / Showmanship horses in performance events like reining, so that may contribute to the long mane being acceptable.