Would an indication of astral projection (for someone who at the time is consciously trying it) be a violent shaking? not that the body would be shaking but it seemed as though something else was kinda like Ashton Koocher in the Butterfly Effect for anyone who has seen that movie (im referring to the part's where he goes back in time and the world kinda freaks out around him)
Feeling energetic vibrations is a very common signpost for most people that they are close to exiting. For many people, once you reach that stage all you have to do is relax and let it happen (or so I've heard). Personally the vibrations don't always occur for me. Assuming that this isn't a negative feeling or painful thing, I'd say you're on the right track.
By the way, not that I guess many of you knew me, but I'm Talon213. My account was inactive, needed a new one. Never posted much, so I doubt anyone remembers me.