Cinco de Mayo calls for a flower crown, don't ya think?
You'll need: 3-5 sheets of colored card stock, glue gun, scissors.
The paper flowers are based on this DIY from The House That Lars Built on Oh Happy Day, with a variation from Tania Fischer Design (if you're in California, I highly recommend Tania's giant flower class).
Make three flowers. Hot glue them to a headband -- glue them CLOSER together than you think they need to be.