This doubles drill is from OnCourtOffCourt. It can easily be adapted to work on a variety of shots and singles as well.
Mark off the middle third of the court from net to baseline. This is the Forbidden Zone. Play doubles. Any shots landing in the middle third mean a point for the opponent. This version will help players work on hitting angled shots.
Now change the rules so that the middle zone is the preferred zone and the outside thirds are forbidden. Keeping the ball in the middle of the court can be a sound strategy in both singles and doubles.
Overall, it is important that players are able to control direction, the third layer of our tennis skills pyramid.