Here is what I do: Use a dumbbell. Start off with 2 or 3 Kg. Stretch your arm straight (shoulder level) and use you fingers to hold the dumbbell. Now, move your wrist up and down - 20 times per session. 20 sessions per day is good enough. Remember to keep your arm level at all time. The key here is to move your wrist not your arm. If you can reach 20 times/session with 8Kg dumbbell, you will have a strong wrist! Have fun!
