Just a heads up, I was going insane trying to get this move to work: I tried following the tutorial about holding the controller upright and moving it in circles, but either the game is a little glitched, my controller doesn't work correctly or I didn't understand the motion, but I couldn't get the move to work constantly. I also tried doing the circle motion holding the controller in a standard position, but had the same results. Anyhow, out of frustration I decided to just shake the controller from left to right while holding it horizontally and that worked great!
It gets trickier the further you get into the game to have this move work consistently, so hopefully this tip helps whoever has trouble as I did. :)
The ballerina power only tends to work over harmful substances, like swamp slime or gas. It can't be used like Rayman's helicopter or anything, i.e. to make it over long gaps. There are certain stages (and at least one boss encounter) where there's a harmful gas or other such substance on the floor. Hold the Wii remote upward and spin it in a clockwise motion to make Pixie spin. It's a little contrived, but it can work - just not in as many cases as the game might suggest.