1) Most club level players slide on clay by accident rather than by design—and they often do it after they’ve hit the ball, which leaves them out of position for the next shot. This is particularly true on the running forehand. When you’re running full speed for the ball, it’s hard to stop yourself from running right through the shot and stopping somewhere outside the doubles alley with no time to recover.
2) The key to the sliding forehand is to plant your outside foot before you reach the ball and slide into the ideal position for contact. Start by turning your shoulders and make sure to keep your non-dominant hand on the racquet, or close to it, as you turn. (This will increase your shoulder rotation.) Run to the ball and then slide into position with your outside foot (the right foot for right-handed players). Your toe should be pointed at a slight inward angle as you slide. The trick to keeping your balance on a sliding forehand is to have a wide and low stance. Your center of gravity should be low and over the middle of your body. Slide into the shot, don’t lunge.
3) Sliding into your hitting position allows you to push off with your outside foot and explode into the shot. The path of your racquet should be low-to-high—use a semi-Western grip—and your hips will rotate and open up into the shot. As your swing finishes across your body, your weight will shift to your inside foot, and so will your momentum. Instead of sliding past the ball, you’re now perfectly set up to recover to the middle of the court.