The other side of challenges is challenge elements that are too wacky/weird to evoke much. I've seen (and been on the receiving end of) some pretty wacky ones, either designed to evoke only a specific scenario (Characters X and Y in a bathtub, e.g.) that you have to work around, if you're not interested in that scenario (those characters standing in the bathtub, looking at something weird in the ceiling), or else just plain wacky (Character Z naked on a snowboard, yes this really was an element).
If you yourself don't write wacky, it takes some hard work to bleed the wackiness out of an element like that.
I did enjoy the "Worst Case Scenario" challenge. It didn't specify fandom or character--it just involved incorporating a given Worst Case Scenario in whatever way engaged a writer.
My favorite quote-found-via-metafandom ever:
I've wondered if fandom is in some ways a convenient excuse for people to write porn
NO! Say it ain't so!
Duh.
Or in my case, frequently romantic comedy with holsters.
We only do it to be transgressive.
If you really wanted to be transgressive, you'd write gen.
Wait, you do write gen.
I need to write more het so I can
really
freak people out.
We only do it to be transgressive.
Except when we're being transitive.
If you really wanted to be transgressive, you'd write gen.
Wait, you do write gen.
Ha HA! I'm a rebel, I am.