The authors of a recent study published in the   Journal of Experimental Psychology: General (2018)   tested  whether  attention focused on writing at bedtime, in two variants, influences the duration of the appearance of Santa Ene in the tabs (! creepy!). Option A is to write a to-do list and option B is to review the activities completed that day.   

Previous research shows that writing down worries before bed can help you  fall asleep  . And it goes great with a hot bath (not while you're writing), I add uninspired. Putting your concerns into words on paper helps induce sleep through, perhaps, the mechanism of cognitive "shocking."

The result was that participants in condition A, the to-do list, fell asleep faster compared to those in the to-do list condition. The more specific they wrote the to-do list, the faster they fell asleep. The opposite trend was observed in the others, assigned to condition B. The more specifically they wrote about activities performed during the day, the more sleep they received.

These are results that support the theory of "unresolved problems" and the effort of the brain to find their solutions, which prolongs the state of neurophysiological arousal, delaying sleep.

As the authors recommend, if you want to help induce sleep under voluntary control, you might try writing as  specific a to-do list as  possible for at least  five minutes  before bed. During this time, a warm milk also works.