You are more likely to remember the details of your dream when you first wake up. By keeping a dream diary you will improve dream recall. Remember first, then write the dream down, and then add as many details as possible. Once you start remembering your dreams in this way, it will become easier to do so. And your OOBE may shift between them.
Imagination plays a key role.
The experience of mental projection is not particularly vivid, and you will more likely be an observer than a participant. Nevertheless, mental projection is an important 'way in' to astral projection proper. This is not true during etheric projection. Etheric projections generally travel at or very near the physical world. But our primary interest is astral projection proper, and mental projection to a lesser extent.