I've known some form of Astral Projection my whole life it would seem and from what I've been told, OBEs is quite similar just a bit more intense. The problem is however, the majority of folks that THINK they have had an OBE or that they really do travel on the Astral plane, don't! It's more akin to a dream-state and what the Rosicrucians refer to as "Mental Projection" which is more like combining our sub-conscious memory with the imagination. It can be a very powerful technique over time, when it comes to personal healing and even bringing aid to others, and it is likewise a gateway skill that can lead you towards true Astral Projection and/or Bi-Location, but such is not a daily event.
If you are curious about this sort of thing I'd recommend that you learn about Hypnosis and specifically Self-Hypnosis as well as a thing that was popular in the early 70's known as the Cristos Effect and/or Alpha Thinking. These techniques will allow you to come quite close to an OBE in a safe manner. I emphasize "safe" in that the New Age culture is filled with nut jobs that will take you for a small fortune if they know you're curious and willing to pay as you go.
EXAMPLE: When I lived in Southern California long ago I was teaching an Astral Projection workshop based partly on the same lecture notes written by Richard Webster coupled with some of my own experiences. I charged (and still charge) $45.00 per person for this 4 hour class. On the other end of this scenario was a New Age jackass based in Beverly Hills that was doing the same exact workshop (using the Webster notes) who was charging over $700.00 a head. . . the irony is, he always had students because
dumb animals think if you pay more it has to be closer to the real thing

The greater irony is that Richard Webster, a noted International author and personality in the New Age world, charges the very same tuition I do though his reputation alone would warrant a higher price.