The entry level nocturnal practice is lucid dreaming, with its vast psychological, physical, and mental benefits.
This has the widest reach and the largest body of literature of the nocturnal meditations.
Lucid dreaming is when you wake up to the fact that you’re dreaming, while still remaining in the dream. Once lucid, you can engage in a host of activities ranging from entertainment to deep psychological work.
In the broadest terms, lucid dreaming is largely about self-fulfillment.