How do you develop forward movement as the first priority under saddle?

Forward movement is the first and most fundamental quality developed in a young horse under saddle, and it must be established before any other ridden skill can be correctly built upon it. A horse that moves forward willingly, with energy and rhythm, from a light leg aid is a horse that can be shaped, collected, and directed. A horse that is reluctant to move forward, that requires strong leg pressure to maintain pace, or that stops whenever the rider's leg is passive has a training deficit at the most basic level that will undermine every subsequent lesson. Developing forward begins with the rider applying the lightest possible leg aid and immediately releasing when the horse responds by stepping forward with energy. If the horse does not respond to the light aid, the pressure is increased — a firmer squeeze, a tap with the leg, or a reinforcing tap with a whip behind the leg — until forward movement is produced, at which point all pressure is released immediately. The consistency of this sequence — light aid first, increase if needed, release the moment the horse responds — teaches the horse to respond to the lightest version of the aid because that is always where the release is available. A horse that has learned to wait for strong leg pressure before moving forward has learned to be dull, which is a training problem that requires systematic retraining to correct. Forward movement should be rewarded enthusiastically in the earliest stages of under saddle work, and the horse should never be allowed to stop, slow, or fall behind the leg without a clear prompt and immediate correction that reestablishes forward energy.