Rub your hands together. This starts to warms them up.
Holding the tips of the fingers, pull the hand gently out away from your body and down. Then, flex back towards the body. Do this a few times. This will give you flexibility.
Like getting the benefit of the wrist flex, hold the tip of the finger and gently flex the finger out away from the body and down. Then flex back towards the body. Again, do this a few times.
Holding your hands in front of you, stretch the fingers on your hands out as far as they will go. Hold for a few seconds and then rest. Repeat a few times.
Make fists and rotate each at the wrist gently clockwise about 10 times then switch direction.
Side to side, and up and down, shake your hands. This simple hand exercise wakes up the nerves and gets blood flowing. This is great before you play as well as after you play during your cool down. It seems very simple and silly but this one actually is one of the best.
This stretches the space in your fingers. Taking two fingers of the opposite hand place them in the web of your fingers and just massage it a bit.
Just massage the palms out to the tip of the finger.