Today I'l like to talk to you folks about control and where it starts. In my experience, I've found that all control starts in the horses face and in your hands. First and foremost, you must have good hands, to feel the bit and how it connects to your horses mouth. I always start gaining control by teaching lateral flexion. Flexion simply means to bend. I start with a very easy, soft O-ring snaffle bit. Standing at their hip, I collect the rein, preferably a thick braided rope rein, one they can feel. I bend him about 1/4 of the way. The object here is to hold steady pressure until HE breaks over. It will not be a dramatic give at first. You will be looking for the smallest of tries. When he releases you release, instantly. You have to be watching closely and know what you're looking for. If you are uncertain, you should really review some of the training videos that are available on the market. Clinton Anderson is good, but my personal favorite is Dennis Reis.
You want to make sure you are not dragging their head around to you, you only want to apply steady pressure and let the horse do the work himself. You want to work both sides of the horse, as they have two brains, one for each side of their body.
He will likely spin like a top when you start, keep on his hip and stay with him. Keep up the steady pressure and bend him until he stops. If his feet are moving, the break doesn't count. When all four feet are stopped, and he gives his head, THEN drop the rein and give him a moment to think about it before you start again.
Brooks Gaited Horse Training