Balloon columns are air filled balloons that are attached to a base of some sort. You can make columns without a base, by using helium filled balloons but your column will not always stay straight up. You can purchase a base or make your own out of wood, PVC pipe or something else that you might have on hand.
Balloon columns are assembled very close to them same way arches are. Here are a few simple steps.
1. Blow up two balloons and tie them together.
2. Blow up two more balloons, tie them together and then twist both sets of two together.
3. Attach them to the bottom of your column base by twisting them on. These balloons should be larger then the next several layers. The bottom and top layers should stand out more than the middle by their size.
4. Repeat steps one and two and then add to your column. Repeat until you have reached the top of your column.
5. Add a large balloon on top to finish it off. To add a little more decoration, stuff your top balloon with another balloon(s) or with confetti.