On the drive back from a recent weekend adventure, my husband and I invented a new game.
We took turns challenging each other with random elements from fantasy or sci-fi. The object was to come up with a new and interesting way to use it in a story.
Some of the prompts we played with were Werewolves, Tree Spirits, People Living in Caves, and Music as Magic.
When one of us collected a few thoughts on how to use the element in a non-cliché way, we talked it out. Together, we developed it a little further, asking more questions, coming up with possible plots and sources of conflict. When we ran out of ideas for that prompt, we moved on.
We actually invented some pretty awesome stuff that I jotted down for possible use later.
Like, “Werewolves: They’re not human and never were. They’re a race of shapeshifters, wolf-like in appearance, whose power is tied to the sun and moon. So when the moon is near the sun and “new” they can shift into anything. As the moon gets fuller and farther from the sun, they have a harder time maintaining anything but their own shape.”
I don’t know if anyone has done werewolves that way before, but I’d read it.
I highly recommend this as a way to flex creative muscles and just play with stories.
Happy Yarning!
All Kinds of Yarns 
That sounds like a super fun way to brainstorm! And I like your idea.