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...Neither of them had ever twirled a full skirt before. Neither had done a tango link and felt what happens around your legs when the dress brushes against it. Neither had waltzed or foxtrotted with that "wind in your hair" feeling, with a skirt moving around them...
I like this. And I agree. I always practice in yoga pants and will continue to do so. They are practical, comfortable, easy to move in, don't wrinkle when thrown in my gym bag before work, and they wash up nicely after I sweat. I would actually feel more hindered in lessons by a $200 Chrisanne practice skirt because I would be worried about stepping on and ripping it, etc. So, yoga pants for me.
However, I do make a point of dancing in my smooth or rhythm dresses prior to any major showcase or comp, even though I've danced in my dresses before. Especially for smooth showcase routines that I haven't danced in costume yet. I notice much more when my skirt spins away from my body, and comes wrapping around my legs, flys up to where I notice it in my peripheral vision, etc. All things to get used to BEFORE the big day. And I do feel differently when I'm in costume. The dress, the hair, the makeup, the "game day" shoes vs my practice pair...they all lend toward me wanting to dance better to match my look.