Vibrations are not really required, you ask a lot, maybe you should try to read more on the subject, I think this website still has articles.
I tryed many articles on OBE and AP, But it didn't really help me, I listened to the radio interview with Robert Bruce and it was just informations.
I just need the right way to project.
I experienced OBEs for a few times and they were very weak and shrot ones.
What is wierd is that I don't get this vibration stuff, I never felt any vibrations before going out of my body and I really don't remember it well, I think that my astral projection is not fine and that I will not get any longer with this methode, it worked to me and after the last 2 times I couldn't do it for about 3 months, and still can't.
How do you get those vibrations and what to do next after getting them??
Thanks for replies, Idan.