The starting point is 'here and now'. Become conscious of your experience. The basis of our doctrine is the consciousness.
Astral Projection happens every night, to everyone. We are simply too unconscious to remember it happening. We just need to wake up - we need to awaken our consciousness.
The point is, we are already existing in that dimension but we do not have cognizance of it. Because of this, we suffer. It is better to not suffer, so, we should awaken our consciousness to know all the dimensions of our Being.