First, you have to decide what you want to do with your horse. You are a trainer when you ride a horse, whether you want to be or not. Training for the show ring, or for sport competition is a lot different than training for the trail. If you just want a horse to enjoy, then simple trail riding is great training. Even a trail horse, however, benefits from arena training to become a well-rounded riding horse, but in my opinion, the best training for a pleasure horse is miles and miles of trails.