Many tennis players now have a 2-handed backhand groundstroke. This anatomically forces your shoulder and your lower body to coil. Very similar to seeing the back of a baseball pitcher before he opens up and releases the ball.
However, on the forehand, the serve, the overhead, the bounce smash and the kill shot, this does not happen anatomically. In order to get the benefit of this coil, you must learn to force the coil. How do you do this? On these 5 shots, take a right-hander for example; keep your non-dominant hand on the racket as long as you can as you take the racket back. This will force a coil and allow your opponent to see your back longer than your front. This will make it more difficult for your opponent to determine where you are intending to hit the ball. Watch the pros hitting a forehand and see how they point to the approaching ball with their non-dominant elbow. Coiling forces a player to hit the ball with their entire body, not just the arm.
Another important tip is to align your body, when attempting these 5 shots, in such a way as to make your opponent think you are hitting these shots to their backhand, (a right-hander playing a right-hander). Most players telegraph where they are hitting their shots because of the lack of coiling. Look at the cover of a tennis magazine and you will see the tremendous coil the pros have on their shots.
Good luck on the courts!