How do you develop the halt and rein-back in a young horse's early training?

The halt and rein-back are foundational control exercises that teach the horse to stop its forward movement and reverse direction from rein and seat aids, and developing them correctly in the early stages of training establishes the communication and responsiveness the horse will use throughout its working life. The halt is introduced first by the rider ceasing all forward-driving aids, sitting quietly, and applying a soft closing of the fingers on the reins. The horse should step into a halt rather than falling into one — meaning the hind legs should step under the body and the horse should balance squarely rather than trailing its hindquarters and stopping on its forehand. In the earliest lessons, any halt is rewarded with immediate release and rest regardless of whether it is perfectly square, because the priority is teaching the horse that the aid means stop rather than correcting the quality of the stop before the concept is understood. As the horse becomes more confirmed in halting from a light aid, the quality of the halt is refined through transitions that develop balance and hindquarter engagement. The rein-back is introduced after the halt is well established, beginning from the ground where the horse already understands moving backward from chest pressure. From the saddle, the rein-back is asked with a soft closing of both reins combined with a slightly driving seat that pushes the horse into the rein rather than pulling it backward. The horse should step back in a clear two-beat diagonal rhythm, straight and without resistance. Any backward steps are rewarded with immediate release, and the rein-back is practiced in short sequences of two to four steps rather than long distances in the early training stages.