Stretching exercises to do before playing the piano include rolling your wrists in both directions, pressing your hands together and releasing and alternating between clenching your fists and stretching out your fingers. The stretching techniques you choose should be comfortable for you; stretch only to the point of tension and never to the point of pain.
Sitting at your piano, roll your shoulders forward, with your hands above the keyboard, and let one of your fingers drop onto a key; it doesn't matter which key it is. Continue this exercise for the remaining fingers and then with all your fingers at once. Use this exercise to develop a natural drop to the keyboard rather than consciously reaching for each key.
Massaging your hands before playing the piano can help make them more limber. Massage each hand thoroughly with the other: Individually knead the muscles along each finger and continue on to the hand muscles. Finish by massaging the muscles in your forearm; although not a part of the hand, the forearm contains the major muscle groups that control the fingers.