Most people do tiny, timid circles that don't do anything. Make them bigger and more deliberate. Lift one foot slightly off the ground and draw large, smooth circles with your ankle and foot. Circle in both directions — clockwise and counterclockwise — with a full, unrestricted range of motion. Your ankle should feel mobilized and loose by the end, and you should notice real improvement in how your joint moves. Don't rush through the movement; let each circle be complete and controlled.