A method for using a light spot projecting aid to observe head movements during a golf swing and to provide a golfer with an explanation (i.e., cause) of the effect manifested as the light spot being moved. The aid includes a light source, such as a laser, that is mounted to a person's head by fastening the light source to a hat. The light source projects a light spot into a hitting area to provide a continuous visual indication of head movement during the swing. The observed path of the light spot movement is compared with a set of cause and effect relations relating swing mechanics to areas covered by portions of the observed path, thereby aiding diagnosis of golf swing conditions.