Think “Exercise” not “Criticize”
From the Horse’s Mouth by Erik Herbermann
It is more effective to keep the horse’s mind on the work by making clear, simple, doable requests, such as: “Do this… (specific request), rather than saying useless, purposeless things like, “Listen to me!” or, “Pay attention!” Furthermore, negative requests, those that start with no or don’t are difficult for the horse to understand. Positive, impersonal requests usually achieve better result: "Look this way", instead of saying “Don’t look out the door!” or saying “ Circle increase, or leg-yield”, instead of taking the horse’s cutting in as a personal affront, “Don’t cut in against my leg!” Take note that in these examples, the trick is to think of an exercise which makes sense to you and avoid making reproachful commands. Like us humans, horses do not operate very well under the gun of criticism or reproving attitudes. Adopting this approach takes the battle out of the relationship and achieves results relatively effortlessly.