One of the writing groups I belong to, I believe it was PLRW, posted this call for urban fantasy/were-creatures short stories from Ekaterina Sedia:
And I thought to myself: well, there's no reason why I can't write something for that. Even if just as an exercise in finishing a new project for a specific purpose. Always a good lesson. Creative people sometimes forget how to complete an assignment that's not muse-driven.
I now have several pages of notes in my journal about a werewolf in post-Liberation 1945 Paris...