Let's start with a good book on the subject, sort of an old school how to of sorts : https://www.dmt-nexus.me/Files/Books/General/Journeys%20Out%20Of%20The%20Body-Robert%20Monroe.pdf
It's robert monroe, journeys out of the body
Second, i suggest you first learn how to work with the energy inside your field before venturing out. If you can look up grounding meditations and get bto know your four directions, so you are at home in your own field, body or not...
My friend and I had a summer up here in Tahoe where we worked on OBE's specifically, we'd meditate in front of the fireplace, and sometimes go up the chimney...come back awake at 3 am and realize we forgot to go together...
When we went home from vacation, we had left behind a notebook with a journal of our time there, we were both worried my folks would find it and we'd get busted for hanging out with the guys across the street (lol)...so in the meantime we are going to sleep with the intention of traveling together or meeting up , etc...
One night I woke up (or became aware) about 3-4 feet above my bed, and m,y friend was floating by my window, I was immediately outside next to her above my house and we 'flew' over the sierras back up to Tahoe...Inside the cabin, we tried to pick up the notebook but realized we'd forgotten our bodies! I still have the most vivid memory of flying close to the surface of the Lake, moonlight and starlight visible on the water, and how free it was, joyful...
the next morning as we drove to school, she began to tell me about the 'dream' she had...and described the whole thing, i was crying by the time she finished, it was a real affirmation for me that we are SO much more than this body-suit 
lastly - I have heard often that flying dream are our rememberance of being 'out' at night, and that we instinctually do it more often than we realize...the key is to become aware INSIDE the dream and realize you are in another reality... it is a trip!
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