According To H.T. part 8

Each day I try to add a little more to what I expect from my horse. You want to have a planned idea in your head as to what your exercise will be for the day. Such as yesterday, I asked my horse to step up into a faster gait. Today, I will also ask him to do that and I will try to hold him there until I ask for the walk. I will go around the ring 2 times to the left, reverse and go 2 times to the right, stop, back my horse 3 steps, ask him to go back to the rail and walk slowly back to the barn. Once I have this pattern in my mind, I set out to stay the course as much as possible. I mostly ride Mountain Horses of which are bred to have a four beat gait but, at this time I am not concerned about his gait. My main objective is to regulate his speed. I will ride him next to the rail so if he tends to drift toward the inside I will apply pressure on the leg opposite the rail to push him back to the rail, so that he follows it in as close a line as possible. You will find that when riding in a ring your horse will know right away where the gate is. To avoid my horse trying to exit before I want him to, I will never let him just walk straight out of the ring. I will ride past the gate, stop, turn toward the center go back past the gate, turn toward the center in a small circle riding straight out at a walk. Always ride back to the barn at a walk. Not as much fun, but your horse will learn patience. :o)