By programming the associations your brain makes as you start to feel sleepy, you can set yourself up for a good night's sleep \x96 or an awful one.
Concrete ideas to modify and expand this hack go here.
Freeform discussion of this hack goes here.
Errata go here.
TomStafford?
This is a page for a hack from the book MindPerformanceHacks by Ron Hale-Evans.