That's the whole thing about powder, you don't have to be on an edge (your edges don't really do anything unless you hit hardpack underneath). It's like surfing, you steer with your back foot and use gentle motions to guide the board. Trying to dig in your edge is a big no-no unless your trying to come to a complete stop. It's a weird transition, but you have to let go of that instinctual urge to try and carve and just float. Make sure you transition some weight to your back foot - you will float better and it will make it easier to initiate turns as well.
PowderHound and TreeNinja