The foundation for developing better footwork from the baseline is the reset positions after you play a ball to your opponent’s court. Instead of thinking of the tennis court as a rectangle that has one center, picture three main triangles that shift as you play the ball into your opponent’s court. Even if you are playing the ball down the middle of the court, you are actually resetting and hitting back into a triangle, not a rectangle. In the videos below, seeing is believing and this is really step #1 in transforming your practice court to developing better footwork and reset positions from the baseline.
Extended video 3 Centers of the Court