This drill is a fun way to practice serve consistency by beginning, as well as advanced players. Beginning players have two serves per point, advanced players only one.

How it works:
The player takes up position at the baseline, deuce side. He will attempt to serve the ball in (two tries for beginners, one try for advanced players).
If done successfully, the player scores 15-0. If he misses, the score is 0-15.
Next, the player serves from the ad side. If the ball goes in, the player scores a second point (30-0); or loses a point. 
Continue practicing serving and scoring until the player either wins or loses a game. 
It can be played continually for a few games, or a set.

Note: 
For advanced players, the ball should be sent with a decent pace - the ball should bounce once, or no more than two times before it hits the back fence.