It amuses me from time to time to look at the
AO3 freeform tag cloud (jeepers, that's gotten large), try to find the most amusing or unlikely runs of tags, and imagine what kind of story would involve the lot of them. A few favorites:
Arranged Marriage, Artificial Intelligence, Asexuality, Assassins
Casual Sex, Catholic, Cats, Cautionary Tale
Las Vegas, Latex, Latin Grammar, Laundry
Pastiche, Pegging, Penguins, Pesach
Vampires, Vermont, Vibrator, Victorian
Play along at home! (I dare someone to actually write "Pastiche, Pegging, Penguins, Pesach".)
The archive should totally have some sort of page that throws random collections of tags at you and double-dog-dares you to write them. :D
ETA: Nazis, Near Death Experience, Necrophilia, Need Brain Bleach
:O