One of the most common strategies in tennis is to get your opponent running. The reason this is so popular is that most players are unable to hit the ball as well when they have to move a lot to hit their shot.
The key to hitting the ball well on the run is giving yourself a chance to take the same, or a similar swing as your normal swing while you are moving. Most players tend to change the swing to try to just make the shot or they go for broke and try to hit a winner. Both of these ideas will make it less likely that you can repeat the swing on the move and under pressure, resulting in many more errors than good shots. Try swinging at a similar speed, with a similar stroke, and with the idea that you can hit this shot and recover after the hit.
I know it is tempting to go for it all or to be sure you just make the shot, but this will not produce the best result over time. One idea that will help a great deal is to remember that most on the run shots happen because your opponent is hitting their shot to the opening on the court. Once you hit your shot, start moving towards the opening so you have a step or two less to run.
Very often, the couple of steps you saved after your opponent's hit will make the difference in your ability to hit the shot well on the run.
Steve Annacone, USPTA Elite Pro, is the Director of Annacone Tennis (http://www.annaconetennis.com) and MyHamptonsPro based in Sag Harbor, NY (http://www. myhamptonspro.com) and Tennis Professional at Ventana Canyon Golf and Racquet Club in Tucson, AZ. For details on lessons, clinics, or coaching, contact Steve at firstname.lastname@example.org or call 865-300-7323