The best method I can recommend is to attempt to build up your biceps. A lot of the time your forearms will naturally take some of the strain (the bicep muscle is a very poorly balanced lever, so the forearm is there to do the job the bicep just can't). Standing Hammer Curls are good ; Hold a dumbell in a resting position with the dumbell lateral to your forearm. Then slowly lift the weight towards your bicep, keeping the dumbell at the same angle as you lift as far as the top of the arm. Bring down again at the same rate. Repeat until failure for about three sets (max fifteen reps). You can also do wrist curls, which involved taking a dumbell weight by the wrist and lifting using only the wrist. You can do this both with the palm facing up and the palm facing down, though usually lifting with the palm down is weaker than when it's facing up and you won't get as much benefit, but if you're wanting overall strength do both sides. Other than that any exercise that uses your arms (particularly anything involving pulling) will usually increase the strength of your forearms.