Beware of Over-Tightening!
Over-tightening the hair of your bow can yield disastrous results, including fracturing at the tip, hair being yanked out, and warped wood. One tried-and-true method of ensuring proper tension is to insert a pencil between the wood and the hair at the bow’s midpoint: if the hair is about a pencil’s width from the wood, then it is tightened to the ideal tension. The hair should be closer to the wood in the middle of the bow than it is at either the tip or the frog. If the hair seems to be equidistant from the wood for the entire length of the bow, it is over-tightened!