The user tapes the tennis racket to his hand with athletic tape. First he wraps each finger with one layer, after each layer he tapes around the back of his hand. Then he attaches the racket to his hand at the angle that he wants.
There are different taping techniques; each user needs to try different ways to see which works best.
NB: never tape thumb in place, it can injure the thumb and cause pain.
Athletic equipment and medical supply stores (tape)
This tip is from 2009