Wagtail
Horse servant
I also found clicker training to be an excellent way of teaching dressage. My mare mastered transitions, changes and advanced lateral moves no problem, but for some reason she just did not 'get' medium trot. As she was so enthusiastic with the clicker training, I taped the clicker to the handle of my schooling whip and when she offered me even the slightest bit of lengthening I clicked. Of course you cannot reward every time when you are riding and so this only works when the horse is well established and the click is a reinforcement in itself. She mastered a very impressive medium trot in only one schooling session with the clicker! When riding I would stop and treat her every seven or so clicks.