I have read many books in the last year about AP/OoBE techniques, but the only thing clear to me now is that everyone who writes a book has a different experience. I was trying different things from books for a while, but I gave it up, figuring that I must not be ready yet. Meanwhile, I keep a dream diary in which I have recorded something nearly every day. I may not always remember complete dreams, but my dream recall is much better than it used to be. More importantly, I know the mental state of my dreams. How can I put this...
In our waking hours, we go through many states of consciousness. We're not simply "awake" but we can be daydreaming, remembering, intently focusing on a physical thing, meditating, etc. Regardless, we're so familiar with these states of consciousness that we don't mistake them for anything but our waking reality even though our minds are often changing focus on a whim.
Dreams can also vary a lot in content and even in degrees of lucidity, but when you return to waking consciousness you know that they were just dreams. At least, you should be able to recall enough to know if the memory of the dream felt like your typical dream state of consciousness. That's why one should write down the dreams: you'll know when you experience an altered state of consciousness that was neither "dream" nor "awake."
I have experienced sleep paralysis in the past. It happened fairly often when I was working long hours on night shifts back in the day. I would be semi-conscious and immobile in the dark with an inexplicable loud noise inside my head. I felt as if I needed to move some part of my body to regain control, but this didn't always work. My fear gradually lessened, and eventually I learned that it was not dangerous. Back then I didn't know this was a means to having OoBE.
Then last month I had sleep paralysis again, not due to any sleep deprivation though. Only this time there was no loud internal low frequency noise. Unlike a dream, I knew exactly where I was in bed, but I couldn't move my body. I did, however, will myself to move. Frankly, it was the weirdest thing I've ever felt. I did move into a sitting position, but I felt stuck in that same altered state of consciousness that I felt at the beginning of the paralysis. My vision was distorted and blurry in my mostly dark room. I could hear my breath, but the sound was like listening through a tube. I stood up, but I had no real sense of balance. I touched my face and felt my clothes as if to assure myself it was real. I moved to the light switch, and I thought I turned it on, but nothing happened. I turned around to look up at the ceiling fan, but the room was dark and blurry. It was right then that it occurred to me I was still in bed. It was a moment later I "woke up." I never have dreams like that. As best as I can figure, it was an etheric projection (finally) that I was able to recall. My etheric senses aren't very good, but maybe that improves in time.
The point I'm making is, become familiar with your mind's various states of consciousness by meditation and dream recall, and keep a diary of your work. If you don't experience AP right away, don't worry too much. It may happen when you least expect it.