Meditate first(what works for you)
After:
Sit down or laydown but not where you sleep, do it in living room or somewhere. Have an object of focus like a picture or your favorite cup. You can set it up as to where you are facing. Focus on it before you sleep for as long as 5 min to get the "feel" for it.
Then go to bed. Now remember the location of the object. Where you were sitting or laying down.
Now visualize, pretend or imagine getting up from the bed and going to the objects' location to focus on it.
Do this everyday and next thing you know you will either float to the object or walk to it.
The time to achieve success is dependent on the individual. If you are natural you can do it the first time.
I succeeded after 8 days.
