Unlike Astral Travel and other forms of intentional out of body traveling, an out of body experience or OOB is usually sudden and unplanned. Many times, these experiences will take place at the time of great distress or near death.
The out of body experience can be a time of great terror as you realize that your body lay behind you or beneath you while you float away.
The key to controlling the experience so that it can be turned into astral travel at a later time is control. You cannot panic. Your body will call you back once the crisis is resolved and there is nothing beyond death to worry about, and that is going to happen if you are in your body or not.