How to Make a Giant Balloon Gift Box (Easy DIY!) Want a show-stopping holiday balloon decoration? This giant balloon gift box is so fun and surprisingly simple to build! Start with two 18-inch balloons, tie them into pairs, and connect the pairs to form a large cluster. Secure the base using uninflated 260 balloons. Add a layer of 10-inch balloons, then another 18-inch cluster on top. Finish the look with inflated 260 balloons on each side to create the ribbon, add a bow, and your giant balloon