Since nearly everyone is cost-conscious right now, I wanted to show how you can create a nice looking centerpiece very inexpensively. Here is a sample centerpiece that we created for a school carnival-themed event. This centerpiece would look great at either a movie or carnival-themed party.  The box was purchased at Party City... We twisted together a cluster of small white and yellow balloons, which were then attached to a weight inside the box (just to keep it stable). We then made mylar poofs and inserted them in the corners of the box and occasionally sticking out of the cluster of balloons. 

Photo courtesy of Party Perfect

Here are two videos from the nice folks at A-BnC Parties demonstrating how to make a mylar poof and then another about how to open the poof: