It really helps to have someone there to yell at you when you're not in the right position. Also, you can video-tape yourself riding that way you can see exactly what you are doing wrong and be mindful of it next time you ride.
I would also suggest riding bareback. It really helps to improve balance and should help you develop a more secure seat. Because you don't have the saddle to provide added stability it will help you figure out exactly where everything needs to be. A couple things to focus on while riding bare back:
1. Keep your leg long. A lot of people start letting their heels climb up the horses side when they feel unstable. A nice long leg will help you maintain your center of gravity.
2. Don't forget to keep your heels down. It's easy to let your toes drop when you don't have stirrups to use for support and leverage.
3. Relax and breathe. One of the best parts about riding bareback is that you can feel your horse's movement. Allow your body to work and flow with that movement.
Last edited by Ink; 07-03-2010 at 11:25 PM.