Originally Posted by PaintHorseMares
If you can get the help of your group, practice circling him from the front (or the middle) to the rear, and have the other riders do the same so he gets used to being in the front, rear and the middle....and practice, practice, practice. It's not unusual for a horse to have a preference for a certain position, and the 'not wanting to be left behind' instinct can be very strong.
Great advice. Patience, however has to be taught for a good trail horse. A good trail horse will take any position he is placed at and will not rush unless asked. There are times you may have to leave your riding partners, may need to allow a lag between horses going over or through an obsitical... the list goes on.