A new story idea every single day.
Ideas can be shit, detailed, loose, tight, scenario-based, character-based, or could just be a single line of dialogue which might later unfurl itself into a glorious tendril of butt-tickling wonder-magic … or something.
Stole this concept from @ryanklindsay.
Check out the previous ideas here.
#365: A man writes 365 ideas down and then finds he's used all his ideas up. That's it. He has nothing left. Oh dear. He then has to go through his life without having a single idea.