Contact Point
The most important part of any tennis stroke is the contact point. Many players focus to much attention to the length of the backswing and the follow through. What's the point of a big backswing and a great follow through if you shank the ball when making contact. Your shots will be more consistent if you keep your racquet moving towards your target on contact. Visualize your racquet staying on the ball as long as possible and then following the ball towards your target.  This action will help you get your body weight into the shot resulting in more control, depth, and power to your shots.