How do you prepare a horse to behave correctly in a group walk-trot class?

Behavior in a group class environment is one of the most practically important preparation areas for walk-trot western classes, and a horse that is well schooled at home but anxious, difficult to rate, or distracted in a group setting will not show to its potential regardless of the quality of its gaits. Group class environments present stimuli that a horse trained exclusively at home may not have encountered — other horses traveling at different speeds and in different directions, horses cutting across the arena or moving up from behind, the noise and activity of a busy show environment, and the spatial pressure of sharing an arena with multiple horses and riders simultaneously. Preparing a horse for this environment requires deliberate exposure to similar conditions in training. Riding in group lessons, practicing at busy arenas, and hauling to outside facilities where other horses are present gives the horse the experience of working correctly around other horses before it is asked to do so in competition. The horse must learn to maintain its pace and frame regardless of what other horses are doing around it — not slowing when a horse passes, not speeding up when a horse moves up from behind, and not drifting toward or away from other horses during the class. These habits are developed through consistent exposure to group riding situations where the rider quietly enforces the correct pace and position each time the horse deviates. A horse that has been to many group riding situations and performed correctly in all of them will be significantly more relaxed and consistent in a walk-trot class than a horse whose show pen experience is its first significant exposure to a group environment.