Eliminate grey areas of pressure. Convince your mind that the horse can feel the slightest shift of pressure. Be self aware of every signal you are giving your horse.
The inside and outside rein and leg is not determined by the direction the horse is going. It is determined by the way the horse is bent. The horse is bent around the inside rein and leg.
Improving shoulder control as one piece of more advanced maneuvers.
Being able to move the hips to the inside helps build lead changes and canter departures.