By take the bit, does she brace against your hands, lock her jaw, and run forwards? Or drop her shoulder and run sideways?
Teach her a one rein stop. Make sure you use a snaffle bit. If you only do one rein stops for a couple sessions, you'll be amazed what it does for your horse's brakes.
Do a lot of lateral flexion from a stand still, both sides. Your horse's stop is only as good as his back, so practicing backing up with energy and getting the hindquarters under the body.
If she braces against the bit and runs forwards, don't keep pulling back. A horse can brace against two reins used at the same time, but they cannot brace against only one rein. One rein stop if he starts running away with you.
Last edited by Brighteyes; 07-16-2012 at 11:02 PM.