This video demonstrates how to warm up your shoulder and elbow to loosen and warm your arm before working on your wrist.
Carpal Tunnel Exercises Shoulder and Elbow Warm-up

After you’ve been clicking the mouse a long time or typing on a keyboard or mobile phone at certain angles, you may experience soreness or numbness in a line that radiates from where your thumb and index finger branch off, through your wrist, and down your forearm. This thumb numbness and wrist and forearm soreness can be associated with a condition that goes by various names, including mother’s wrist, washerwoman’s sprain, Blackberry thumb, de Quervian syndrome, and radial styloid tenosynovitis.

Only a medical professional can diagnose if you have a technical syndrome. But when the problem is simply that part of your arm has become fatigued or inflamed through overuse of certain muscles and tensions, you may find it helpful to take a break from the aggravating activity and stretch out the sore spot. Here is a simple stretch I’ve found helps me if I get sore in this area from too much mouse-clicking or typing:

You can also brace your hand in a similar position against a wall or door by placing your arm in front of you angled slightly down.

If your wrists are equally flexible, you can brace your hands against each other this way as if in a prayer position with the fingers pointing downwards.

Here’s an easy exercise I sometimes do to warm up my arm before typing or when I’m feeling stiff:

You will be surprised how fast this loosens you up and warms you up. It’s great to do this before you start any wrist stretches because it gets the blood flowing to your wrists.