Tom Gellie explains why carving on one ski is hard: you need inside-leg hip adduction, not just tipping your body inward. Practice the movement with a mirror to check your hip position, and train both sides equally for balanced turns.
Chapters
If you can't carve on one ski, it's probably because you can't make this move with your inside hip. It's called adduction, and it means you don't have to tip your whole body inside like this. Demelza does a great job of demonstrating the right hip position of the inside leg. Watch Skelly again to get this hip adduction movement in your mind. I won't lie to you, this movement is really hard to train. However, if you can incorporate this inside leg movement by doing some one-ski ski training, it will really help your overall skiing and both legs being symmetrical throughout the ski turn. The best advice: get in front of a mirror and see if you can emulate that inside hip position, then get out and practice on both sides like Demelza does here, and you'll find your skiing improves drastically.