It might be kind of annoying in class, but I do a ball-tap thing all the time. Which is the technique I find easiest for fast doubles. Come down with the ball of my foot and tap down on the toe on the upstroke. I'm not doing continuous things, I just want to be able to hit the double stroke in linear fills.
I recently saw a thing from Mike Johnston (I think) where it was suggested practicing something slowly and carefully to get the muscle memory in place. So you could do a quiet heel-toe thing where you are slowly paying attention to the position of your leg, ankle and each tap.
Of course you should be paying attention to class.