I'm on the Etsy Bookbinding Street Team. We've recently been given a team challenge to create a book that represents the festival season (Carnival, Mardi Gras or whatever festival you have this time of year in your portion of the world.)
Carnival, in my mind, is really just frivolity and light heartedness, and the best thing to symbolize that would be the jester's hat or fool's cap. Click here to see the book in my shop or GO VOTE! on the etsy team blog by using the poll on the right side of the team's blog.