Self-hypnosis means to get into a light trance. You don't need to go deeper than low alpha waves. You don't feel the trance, just as a deep relaxation, but the physical world around fades somewhat, and you can give suggestions to your subconscious, can regress in time, including past lives, can ask for guidance from a higher guide, ... All / most of these could be achieved through meditation too, but you can achieve them faster through self-hypnosis.
On a recent thread the OP described some of their experiences with self- and hetero-hypnosis, and suggested a hypnotist's site that I browsed a little, and seems to provide useful information:
http://www.spiritualforums.com/vb/sh...d.php?t=126306