The Belly to the wall drill promotes proper body alignment and balance in the water. You can use fins and a snorkel but eventually you want to remove all equipment. The key to this drill is proper alignment between the front and back of the body. Since your lower half is not as buoyant as your upper half make sure you are applying pressure up front. You can even start with a kick board under your lead hand. Keep your stomach slightly closed to the water versus over rotated towards the sky. Your head position is the same as when you swim. Breathe by rotating your chin up. Don't lift the head and turn. Top hand stays on your hip. Push that hip into your hand.