Abstract: An apparatus for temporary use with a golf driving range mat or ground practice area in teaching the proper stance for a golfer when swinging a golf club to hit a golf ball placed upon a tee inserted into the mat or the ground. The apparatus comprises first and second strips of flat elastic material. Each strip has a length selected so that the strip will be under moderate tension when it is stretched across the mat from one edge of the mat to the opposite edge of the mat and held against the mat by a discrete anchor at each end of the strip.