From what I understand, the float-y feeling is probably just a test. Once you start feeling more intense things, try imagining yourself flying out of your bed, or rolling off your bed and then standing up. I did this last night and it worked, even though I felt like I was flying one-way through a vortex. Or, if you're far enough into the transition stage, even imagine someone coming along and helping you up by pulling your arm. This could manifest itself and pull you into a dream, if I'm correct.