Hi pw-rangers,
Two exercises that my trainer had me work on that might help you:
1. I stayed in two-point, with my seat completely out of the saddle, in all of my flatwork--walk, trot and canter. I had to build up to this, but eventually I rode just about the entire lesson in two-point. This made me a much stronger rider. I learned to balance over my base of support while off my horse's back. If I ever felt as if I were going to fall back, I'd grab mane.
2. My trainer set three small jumps--crossrails to start--side-by-side, and I jumped over them in a serpentine pattern in two-point. Again, I had to focus on staying out of the saddle, but not throwing myself forward and jumping ahead. The jumps were small and the pattern was simple, so I really could focus on letting my horse jump up to me. Again, if I felt I were falling back, I'd grab mane.
Hope that helps.
Sandy