If you want to learn to carve well, any of the traditional "inside ski lightening" techniques will do nothing but set you back. I have spent an inordinate amount of time unlearning
this sort of skiing over the past year. If you aspire in any way to leave RR tracks, you will not get there by putting the majority of your weight on the outside ski. And at least for me, getting better at the two-footed thing has improved my skiing across a broad range of terrain and conditions. And it seems especially key to getting the most (or even anything) out of some of the more modern ski designs like the higher end Metrons. .
I like Atomicman's suggestion. Visualizing the results of sliding the knee outward (especially outward from the other knee)has helped me get the hang of using the inside ski - and stance width. A combination of thinking about rolling weight onto the soon-to-be-inside little toe edge and motivating angulation by pushing the soon-to-be-inside knee out has worked best for me. Note that this is very different from lightening or lifting the soon-to-be inside foot/toe. If anything, I concentrate on keeping weight on that edge...
Also, having been somewhat used to weighting the outside ski - I have had to emphasize weighting the inside ski quite a bit. When I was just starting on this, I tried to get 90%+ onto the inside ski - and ended up with maybe 50%, which was still not really enough to generate even arcs. It has gotten easier over time.
The other thing that killed me for a long time, and still gets me sometimes, was allowing one ski to lead the other which made it hard to bang out truly parallel arcs. Been working on using my core to keep the tips even (with any number of "tricks" to try to make it happen).
Disclaimer: Just describing what has been working for me. I know I still have work to do though.. I am not an instructor. I have no intrinsic bias toward anyone's official doctrine. And I may well have mangled official jargon here. Tough!