I have noticed over the years that I sleep more deeply and peacefully if I have made the bed before getting into it again. Smoothing out the sheets and the covers and fluffing the pillows after waking, releases the energy of the dreams from the previous night. This helps make sure that each returning to sleep is a new experience, an opening to the possibility of entering a wonderful state.
The principle of sauca (cleanliness or purity) invites us to be clean and clear before and as part of our physical and meditative practice and all our living. Imagine trying to practice yoga on a dirty mat and going into savasana (corpse pose/final relaxation) on a tangled blanket. Would you think it possible to become deeply relaxed? Probably not. If we want our space smooth to lie down for a yoga pose, how could we not need the same for a good night’s sleep, for a planned visit to another state of consciousness?