Another way, this works like miracles. Put their saddle on, and put potatoes on the saddle firmly, so they won't fall off. let him buck around the arena/pasture (or just an area where he/she isn't gonna get hurt) and let him/her go crazy. When the horse is tired, take the potatoes off and you get on. He/she will be too tired to buck. And when your done, give the horse a treat. I swear, it works.
