text: Walk the dog is a trick where you are basically using the tennis ball like a basketball bouncing it between your legs as you walk.  Spinning the racket on your finger is self explanitory.  Catching a ball in mid flight without a bounce requires you to catch and cradle the ball as you turn the racket over while decelerating the ball in harmony with the take back of your racket.  Throwing your racket in the air spinning fast and catching the handle a la Hicham Arazi the magician, is the best I have ever seen at this.  Also there is spinning the racket around your neck and onto your other hand, which is very difficult and I have only known a couple of players that could do it.  There is some other tricks to, but explaining the racket motion requires a lot of typing and is not easily explained without having seen it done in person.