Most new owners welcome any tips on how to keep their new charge healthy. For example, if you have used a coat or hoof supplement, tell the new owner. After all, you have spent hours and days getting to know your animal, and there is no reason to let all of that valuable information go to waste. It might seem like minutia, but a new owner will appreciate any tips from you. But before he goes, you have some work to do.
Aesthetics play a huge role in the show ring, and in a sale.
Your ongoing grooming should keep your horse's coat shiny and glowing. On the day that you show him to a prospective new owner, make sure you groom him meticulously from head to heel. A good curry, followed by a smooth finishing with a soft brush is critical. Wipe his eyes, nostrils and ears, and make sure there are no shavings in the tail. Clean his hoofs as carefully as you always do, and brush on some hoof polish.