The finished pumpkin can be used as a reusable jack o' lantern, candy bowl, pumpkin-top hat, door decoration, scarecrow head, etc.
Step 1: Supplies
Stick (approximately pupkin stem width)
Round piece of cardboard
Washer/smashed bottle cap (optional)
Cutting device (Dremel, scissors, sharp serrated knife)
Hot Glue Gun + spare glue sticks
note: not all supplies are pictured
Step 2: Prep Balloon
2. To tie the strings together hold all of the loose ends together and pull them through a loop, trying to keep the ends close to the knot as pictured below. Now take the balloon and blow it up again with the strings draped around it. Holding the knot at the top, blow the balloon up enough that the strings don't move around too much on their own, but enough so you can adjust them to make strait loops alternating around the balloon.
3. Once you get the strings straight enough (I followed the lines on my bungee balloon), carefully continue to blow your balloon up until you get a nice shape with ridges. It may take you a few tries, patience!