Hello.
For a long time I would try and "push' things to far - I would mentally attempt to force myself ob when the vibrations started. This would either cause a moment of change (momentarily ob maybe) or I would blast off into some short-lived, out-of-control projection - either way they were always short-lived and a little annoying. Like you say, this could happen several times in one night.
I got over this by sitting back and enjoying the vibrations and gently, gently easing myself away. I would do this by either moving my astral body out of the physical or by playing with opening the 3rd eye - this would lead to imagery that would sometime act as "gateways" to a projection.
So enjoy what great advances you've already made, would be my advice.
Good luck.
t
LapSiLap -
If your projections are short, unfocsed and confusing then you might want to focus on a specific intent before sleep. That intent could include visiting a person or place. That will provide motivation to leave your place of residence while out of body.
Last night I felt the vibrations.. I rolled out and then i stood in my room. I went through a door and then into the kitchen where i looked at the clock, which time it was. 10.50 AM. Then I was back in my body. Though it was only 1 in the morning :(
I then closed my eyes and tried OBE again.. I soon felt the vibraitons again and rolled out.. I felt that I really came out of my body but when I try to see I was still in bed.
Usually after that I can get the vibrations within a few seconds easily and then i will roll out and then find myself still in bed. This can happen 5,6 times a night and then I just get tired and fall asleep.