Lefty serves are difficult for one reason: you simply don't see them as often. By finding a left-handed hitting partner, you'll be able to get more reps.

A lefty slice serve naturally moves to the returner's left, so you'll want to position yourself to the left of the serve box when lining up to return. And by going down the line with your return, you'll give yourself a better chance of being in position to hit a forehand on the next ball.

Marty Lukosiunas is a tennis professional at the USTA National Campus at Lake Nona in Orlando, Fla.