Ground reference maneuvers and their related factors are used in developing a high degree of pilot skill. Although most of these maneuvers are not performed as such in normal everyday flying, the elements and principles involved in each are applicable to performance of the customary pilot operations. They aid the pilot in analyzing the effect of wind and other forces acting on the airplane and in developing a fine control touch, coordination, and the division of attention necessary for accurate and safe maneuvering of the airplane.
Three basic ground reference maneuvers are rectangular course, s-turns, and turns around a point.
AFH Ch-06 Ground Reference Maneuvers

AFH Ch-06 (06) Rectangular Course
Cessna SOPM 2-60 Rectangular Course

AFH Ch-06 (08) S-Turns
Cessna SOPM 2-64 S-Turns Across a Road

AFH Ch-06 (10) Turns Around a Point
Cessna SOPM 2-62 Turns Around a Point
91.119 Minimum safe altitudes: General.
Private Pilot ACS Page 35 Task B. Ground Reference Maneuvers