Before applying the orthopedic casting tape on the broken limb, slide a tubular stockinette over it. The stockinette will wick sweat from your skin to avoid bacteria growth and other problems. Next, cushion between the limb and the fiberglass casting tape by wrapping it with cast padding generously around the limb. Since the fiberglass casting tape may make your hands sticky, put on some surgical gloves before starting the wrapping process.
You have a choice of using the dry or the wet technique. For example, with the dry technique, wrap the first layer of fiberglass cast tape in half strips around the limb before applying room temperature water to the fiberglass tape with your gloved hands. Then, wait a minute or two to allow it to set before applying the subsequent layers with the same technique. The main difference between the wet and dry techniques is the wet technique requires the cast technician to put water on the tape before application.