In ski school classes, you are taught to stand correctly on your skis with your chest to the valley and your back to the hill. Try positioning your body completely opposite. Ski down the slope and turn sharply with your upper body so that you are close to looking straight up the hill (remember to keep a sharp look out for other skiers). On the whole, try to challenge the "right" stance that you normally practice. Stand as stiff as a board for example, and lean from side to side when you turn. Or start a turn by turning your arms from side to side, and then let your body follow.