The only way I've managed to get myself in a (partial) OBE was by dreaming. Kinda. I got in a voluntarily-induced state of hypnagogia, then simply meditate there in bed for a while, waiting for the visions and such to come along, ignoring them for some time. It's kind of like a lucid dream, yet you experience the dream from a wakeful state of mind. In dreams, the barriers between your conscious and subconscious minds breaks down, letting you control it much more. That's when, after a few trials and error, I managed to get my arms out. I never tried again afterward, not because I'm afraid of leaving my body or something like that; I just never feel like lying down for an hour doing nothing. Have you ever slept without sleeping? It's a pain. (And sometimes the visions come from nightmares rather than dreams.)
I should try again; I wanna have an OBE :[