Zombie World would be a good resource to research for this, as would Untold, the Rory's Story Cube RPG that hit and then was gone. I bet Tarot-sized cards would work for this, both for interpretive/inspirational art and some written prompts. I believe DriveThruCards has a template for them, which means you could print a slick prototype deck.
I just looked at Zombie World, and there's a lot of inspiration there. Building the setting using cards, resolving with cards. I've been wondering if I should have more card types, rather than relying on a really large number of "Scene cards" that might be setting, might be action, might be description, might be events. Zombie World delineates things really well. I'll have to playtest and see.
Thanks for the tip about DriveThruCards!