“How do I keep my onside and offside turns symmetrical?”
This is the question I hear across the slalom world on a consistent basis. To prevent your slalom style from being “lopsided” from turn to turn, you need to work on keeping a neutral stance over your ski. This will keep you balanced from front to back and will allow the ski do more of the work. In both my onside and offside turns you can see that my position on the ski is similar and I have even weight on both feet. A balanced position on your ski will bring consistency and symmetry to your slalom style.
Because of your foot position on your onside turn, it's easier to fall in and shift your weight back on the ski. Falling in is good – but shifting your weight back can be a killer. Rocking back on the ski may result in a tight turn, but it nearly always causes a stall and a position that is hard to ski away from. The key to a smooth onside turn is to keep your weight more forward and balanced.
On your offside turn, rearing back is rarely a problem, but we all know about being too far forward, called breaking at the waist. To combat this, don't ride too far up on the front of the ski. Your ski is symmetrical and will work just as well on the offside as the onside if you ride the ski in the same place. Work on good knee and ankle bend and not letting your shoulders get in front of your hips.