I'm not sure there is a way to get complete control, the nature of OBEs is quite a random thing - at least for me it always has been. Well I say random, I think some part of you knows where it's going, a bit like with dreams I guess.
You could try doing it while you are awake, there's a few books on the subject. I have a book here called
Practical Time Travel that I've owned for years. My first experiments with OBEs were from the first chapter of that book, it actually kind of scared me at the time because I'd never heard of it before I bought that book and wasn't expecting to start floating above my body.
Also it looks really funny when your friends read the title on your bookshelf.