The backspin slice

Backspin

Okay so you've been working on your shots and you have them down pretty good. What's next? A good step to go to once you can confidently hit 8/10 or 9/10 shots without 'pattycaking' them over the net is the backspin or back slice.
This shot can be done from either the forehand or backhand side. To hit a  back slice, start in either your normal or a continental grip. (Try out both and see which feels more natural for you.) Start with the racquet high as opposed to low or waist high. Make sure you have about a 45 degree angle on your racquet head, not vertical or horizontal with the court, but somewhere comfortably in between. Bring the racquet through the ball, keeping that angle throughout the shot, and bring the racquet slightly downwards with your swing, ending at about your waist. Keep visual contact with the ball, and leave your head down as you would with any other shot after the hit is made. It is very important that you retain the angle your racquet head makes throughout the shot or you may end up hitting the frame or fail to have enough power to hit the ball over the net.
This shot on the backhand side can be done either one or two-handed. If you try the one hand, make sure you bring your weak hand up to the bridge or throat (shown below) of the racquet to stabilize the shot. 

Parts of a racquet

Then, as you swing, let the racquet come out of your weak hand and bring it down through the shot, keeping your weak hand up in the air as you swing.

This is one of the harder shots to understand the 'feeling' of how you should hit the ball, and by that, one of the harder shots to master. However, once you add this shot to your repertoire, it can be a great tool as it can be used for offense, defense, or a neutral shot.