Isolations

Examine your fingers. Note that each is made up of three segments and three knuckles, all separated from your wrist by amass of rigid bones and tendons.

Keep the hand facing down and flat to start. Raise the base of your hand so that your wrist goes up In the air. Now, lower the wrist, but as you do, raise the knuckles of your fist. Then, push the fist knuckles down, at the same time raising the knuckles in the middle of the fingers. Finally, lower the middle knuckles and have the finger tips follow like a wave.

Try to make this wave as fluid as possible. The knuckles nearest the fingertips are the ones which will probably need the most work. (They're the ones we use least in everyday life) 

A hint. this exercise is easier if you put the hand to be exercised on top of your other forearm. Walk the hand down the arm like a caterpillar walking towards your elbow. Lift the base of the hand and move it forward, causing the rest of the hand to lift and move forward.

Stronger, more flexible bands will help you more than you think. All of the exercises described here can be done at any time: while waiting for a bus, while watching television, and even backstage while waiting for your cue to go on. I've seen some students make huge gains in body confidence on stage after simply concentrating on their hands for awhile.    

And don't limit yourself to what you read here (or to what you are taught in class). Create your own exercises. Find out where you are lacking and push yourself to improve. Its easy to say, "I don't know what to do with my hands." The challenge is to show yourself the answer.