It is natural to run to where you believe the ball will end up on the tennis court. If a player can move in that direction and also go slightly towards where the ball is (forward), this will take time away from their opponent.
Try to make the last few steps a little more on a diagonal to cut off the shot and to reach the ball at, or before, the peak of the bounce. You will put a lot of pressure on your opponent by getting the ball back to them just a little sooner than they were expecting. This tends to produce more errors as well as making their shot less offensive even if they are able to make it.
Your footwork can be a weapon when used with this idea in mind.
Steve Annacone, USPTA Elite Pro, is the Director of Annacone Tennis (http://www.annaconetennis.com). For details on lessons and clinics at Sag Harbor Park Tennis and throughout the Hamptons contact firstname.lastname@example.org or email@example.com or call 865-300-7323