i think telling people to "lean back" isn't the best way to explain pow skiing. if you simply lean back your center of gravity is way off and turning will be hard and ugly looking, the difference is more subtle than that.
one way I try to tell people how to ski in powder is to put your weight on your heals So like, you know on the groomers and tricking off jumps it's all about putting your weight on your toes and popping off them to initiate shit right? well, while keeping your hands in front (athletic stance), shoulders open to the fall line, and your core centered over your skis transfer your weight to your heals from your toes. your legs will get worked at first because you'll be using slightly different muscles, and you'll probably fall a lot to begin with but that's the advice I will give. Hopefully you get lots more pow out on the east coast so by the end of the season you'll be dropping cliffs into bottomless and loving it.