An exercise Martin uses at his clinics to help rider’s assess their balance in the saddle is riding in a serpentine. When the horse’s nose is tipped to the left, your weight should be pressing in your right (outside) stirrup. This enables him to freely lift his left shoulder and move in that direction. If you’re leaning to the inside, your weight will make it harder for him to move, and he’ll have to find ways to compensate.