Simple and effective exercises for a pain-free wrist

Recently, I gave some advice to a guy who appears to have a chronic wrist injury due to his bboying activity. My advice apart from him seeking medical advice (which he probably will ignore till it gets worse), was for him to strengthen his wrist and forearm while avoiding movements that aggravate his injury.

Exercises such as squeezing a tennis ball or wringing the water out of a wet towel are convenient and easy to perform. Just wring your wet clothes or towel during a bath. You don't even have to sweat to have a good wrist and forearm workout!