When your fingers are really sore and tired from typing for hours on end try this simple reviving technique.
Using a non-greasy lotion (Aveda Rosemary Mint is very nice for the job) deeply massage your palm with the thumb of your opposite hand. Especially work around your thenar eminence (the ball/base of your thumb) and the web between the thumb and the forefinger.
Then using the flat tip of your thumb and first knuckle of the forefinger, circle each large knuckle in turn at the base of each finger. Continue up the fingers doing each set of knuckles.
Then using the first and second finger of the opposite hand bent and opened like a set of vice grips, squeeze down gently but firmly on each finger in turn at the base by the large knuckle and slowly pull and twist the finger along through the "vice grips" ending with a little flicking motion and snapping sound at the tip. This reinvigorates the blood flow to the digits. Repeat for opposite hand.
It's nicer if you can get someone else to exchange with you but still very effective to do it for yourself and even better and healthier if you do it regularily.
See also HealthyBodyAndMind