- If male, not masturbating may help.
If male it is also often found that not getting laid an enormous amount can also help when it comes to goal focused motivation. To resolve the ambiguity, that does not mean "frequently or for an extended duration do not have sex" but rather "do not be in a position of getting an overabundance of sex or sexual variety". I am not aware of any studies, but anecdotal observation and expert testimony is at least somewhat credible, particularly given that this is what I would expect the influence of satiation to be in general.
It is alleged that Bertrand Russell was once asked why he'd stopped devoting much of his energy to philosophy, and replied "Because I discovered fucking". (This is one of those stories that would be much funnier if actually true, but I haven't yet been able to find any good evidence for whether it is or not.)
Checklists are powerful, and I don't use them enough. You probably don't, either.
Below are some of my own checklists. Please share your own!
I don't know how to do X.
I don't understand X.
I feel mentally exhausted but can't afford to sleep right now.
I don't want to get out of bed, but I should.
I'm procrastinating on task X.
I'm about to send an email / post a comment of some significance.
(I don't do these ones nearly enough! D'oh!)
I feel sad about not doing a better job at X.
I'm about to make a decision of some significance.
I could go on, but... what are yours? (Now is also a good opportunity to make some checklists for yourself, based on what you think tends to work for you.)