Your skiing stance is essential to your success in keeping your balance on the move oven uneven terrain. Improve your stance through an awareness of the width of your feet:
Explore the width of your feet. Standing on a level surface, hold your poles straight up and down against the outermost part of your hips. Now create a stance where the outside of your boots is aligned to the inside of each pole.
With this hip-width stance, identify how far apart your knees are and focus on maintaining that width. Beware the part of the turn just past where your skis face down the hill; this is the point where the feet tend to want to come closer together. Unload that tendency and improve your turns by keeping your feet hip-width apart.