Your horse pretty much knows exactly where his feet are and what is around his hooves - this is called
proprioception and occurs because the nerve endings in each foot sends messages to the brain about what the foot is doing, and going to do, with the surface near, around and under the hoof. There is communication back and forth between the hooves and the brain. So, he automatically knows what to do and how best to do it. He was born with this as a prey animal.
He does not need you to micromanage him and steer him around the rocks or fallen logs or mud or whatever. Give him the respect he deserves and allow him to be the horse that he is.
If your horse trips a lot, he simply is not paying attention and is zoning out, unless he has a physiological or neurological problem.