The purpose of the belt is to apply gentle resistance to your breathing so that you breathe lighter throughout the day and at night. You are breathing lighter when you feel the sensation of a slight hunger for air or desire to breathe more.
Wrap the belt around your diaphragm so that it sits midway between your navel and your chest. Tighten or loosen the straps on each side of the belt to achieve the optimum resistance to your breathing. If you feel no air hunger, then tighten the straps until a tolerable air hunger is achieved. Conversely, if the air hunger is uncomfortable, then loosen the straps to achieve the optimum air hunger.