If you have several courts to work with, you can set up a tiebreak-playing court and a practice hitting court (practicing with a specific purpose of course)
Winner stays on, other guy switches with someone from practice court, ad infinitum...
If only one court, perhaps king of the court? (or king of the court doubles)
(i.e. one person is the king, feed starts a point, a person needs to win 2 pts in a row against the king or they switch out)
hope this gives you some ideas. cheers