Myself as many others have difficulties exiting your body through a meditation of intending to astral project. I have only had a few experiences myself, but am having a hard time now. Do you have any suggestions, maybe observations about yourself/life that helps? I do smoke marijuana, but I have exited my body through a mediation on marijuana before
My understanding of this stuff is different from most people's. Astral travel is like dream travel. OOBE are etheric body travel. Not astral travel at all. I have only know in person one person who had that happen. It is also my understanding that people of a certain level of initiation into certain systems have astral body entirely burned up by kundalini. Also, from Crowley I know that travelling OOB without a host of magickal armaments and training in banishings is a totally moronic thing to do.
you can try these meditations to see if they help: http://schoolofdreaming.com otherwise there are many techniques about astral travel in magick books