How about this: We start with a basic, even clichéd situation, then add a detail, twist, or clarification. Then we add another, and so on, until we have made the idea into something different or even unexpected.
To begin: The elves of the ancient Gloamswift Forest have vanished, leaving their (clichéd) treetop homes abandoned. No word has come to the nearby human village that explains their flight.
