Blisters tend to occur over bony prominences such as the knuckles of the toes or on the weight-bearing portions of the foot. Shoes that are too tight or too lose can cause these injuries. Make sure you wear comfortable, well-fitting shoes and break new shoes in slowly by only wearing them several hours a day for several weeks. Socks are also very important and often overlooked. Wear wool socks or synthetic socks. Cotton socks hold moisture against the skin which increases the likelihood of blisters.