There are also a couple more methods I've read about:

One is to simply wake yourself up into full sleep paralysis and deep trance - and then use an OBE/AP exit technique

The other is an in-dream technique I've read about a few times, in which you close your eyes and fall back - with the intent to begin an OBE. I've accidentally done similar to this by closing my eyes and I ended up in the 'void' - becoming only my conciousness as energy, with no body and no location, just thought. I soon made myself return to the dream I was in but it was certainly an interesting experience.