Generally, if the horse gets away with something once, it will try to do it over and over again. When the horse stands quietly in an empty arena we can let other horses enter it and exercise the horse in a halt in the presence of others running around. If the horse gets used to praise and awaits it, it will stand quietly among any noise and movement around. Do not punish the horse for a sloppy stop. Corrections should be made gently but persistently.
Nostrils are on the level of the horse's hip.
The front legs on one line, hind legs are under the body and also on one line. Executing the correct halt Raise the snaffle bit, with even pressure on both reins, to transfer the weight of the horse backward. Strongly apply leg-aids to engage the hind quarters under the horse's body, and finally take the horse on the curb bit. In other words stop the horse in between legs and reins. The horse is now stopped collected, with its hind quarters under the body and not stretched out like a cow.