The classic newspaper hats, paper boats and origami from our childhoods.
If you can't remember how to make one, just go online and do a quick search for "paper hats." There are multiple sites with step-by-step instructions. Once you've folded your designs into shape, use a hole punch and some craft yarn to make contrasting details. Consider making a series that are each a little bit different and hang from a clothes line or pin to a wall for a really fun display.