DIY chandelier. I would string strands through the middle and hanging down as well to make it a bit fuller... OR find a (or a couple of) progressively smaller sized hula hoops and create more tiers below.
If you really want to get creative with your cookie cutter creations, use letters to spell your guests' names out of melon. They'll never mix up their drinks again! Click through for more on this and other summer watermelon hacks.