Envision two vast rooms. One is dark and lit only by the dancing flames of a lit fire. Shadows are long in this room and no light except the Moon's shines in through the tall windows.
The other room is a bright duplicate of the first. It is the same room only during the daytime when the full warm light of the sun reaches in and illuminates all that goes on in the room.
A single doorway connects the two rooms. Imagine yourself starting in the sunny room and crossing the room where everything is clear and easy to see. When you arrive at the door, open it and allow the light of the sun to shine into the darkened room showing you what lies in the sunny room's twin. Try to clearly define what you see, and what your cannot see. Each time you perform this exercise, try to discover more and more detail from the darkened room.
The symbolism of the two rooms represents the two vehicles that are the conscious and unconscious minds. Figuratively, we use one vehicle during our waking hours and another as we sleep. The trick to being able to Visualize clearly, come in being able to bridge the gap between the two minds. When you can stand in one room and use the light of the other to see what is hidden, you will have mastered the power of the unconscious mind, the part of you that is capable of clearly imagining and enforcing the will of your conscious (waking) mind.
If you must, allow yourself to take a few steps into the room, but not more than a few. The idea is not to occupy any one room exclusively but to use them both together. When you have finished the discovering the room in as much detail as you can, close the circle and write down what you saw there.