A psychic should relentlessly work on connecting to the subconscious and maximizing its full potential.
We all spend about a third of our lives asleep - and we don't even think much about that part of our lives. Having physical form constantly puts a strain on our consciousness and sleep is a way regenerating the damages.
For a psychic, sleep is a direct way to interact with the subconscious. By not neglecting this part of our lives, we can achieve a more restful, more insightful, or more efficient sleep.
Psychic sleep is about being conscious about some of the functions sleep performs (such as properly integrating waking experiences) and hastening psychic progress. Generally there is a wide gap between waking and sleeping consciousness, resulting in inability to transfer experience from one state of existence to another. The more caring approach of psychic sleep aims to reduce that gap.
Practical advice for everyone is when you are about to make a bigger decision or unable to solve a problem, get a good night's sleep. Psychic sleep is simply an extension, a conscious approach to this common sense advice.