I always like to start a horse at a walk on a long rein. A horse in nature is a flight animal, and the more comfortable they are with their surroundings the more mentally and physically ready they will be to begin work.
Reading a horses expression will help you to know how to communicate with them by understanding what they are feeling. Expression is the look of their eye and the movement of their ears. If both ears are forward, they are interested in something besides you – they are looking ahead. If the ears are continually back toward the rider, it could be that they are not happy. Ideally you want the ears moving back and forth so they are listening to you and aware of their surroundings. If a horse gives a primal sigh or a sneeze, as they call it, then the horse is beginning to relax. When you hear this you know you can begin to relax too because the horse is comfortable with what is going on. If a horse licks their lips, then that means they get it, they understand.
Horses don’t fight you because they are mean or want to fight, they do it because they don’t understand. If you read and understand them, you can communicate better and, in turn, become a better rider. I did a video topic for EquestrianCoach.com that address this exact question. You can find it by clicking here.