I am very much in favor of live ball drills, playing a lot of points, games, sets, tiebreakers, and any other competitive practice situation. However, one of the best drills that I have found to get your players to swing consistently and with the same follow-through on every shot is a feeding drill. It is very simple, but extremely effective.
The player starts in the middle of the baseline. The coach feeds random balls standing between the service line and the net, trying to time the feed with the player's shot passing their position. The coach should feed medium speed balls, fast, slow, flat, topspin, slice, deep and short. The player must follow-through in the same spot (I prefer right hand to left shoulder and left hand to right shoulder for players with a two-handed backhand) regardless of the type of ball the coach has hit. We want the player to make the shot but, more importantly, we want the same follow-through happening on all ten balls.
This idea is what separates the best players from the rest. You will see Rafael Nadal use his crazy forehand follow-through with the racquet twists or the finish on the same side of his body every once in a while, but the majority of his follow-throughs are consistent. Try this same drill feeding from deeper in the court and eventually all the way back at the baseline.
Keep emphasizing the same follow-through on all ten balls and you will be amazed at the player's ability to hit shots they never dreamed of, even when they are on the dead 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 email@example.com or call 865-300-7323