I remembered seeing a tutorial once where someone cut up plastic water bottles, colored them with markers, and then melted them to make beads. Since most of the cups we get are already pretty colorful, I thought the soda cups would be even better.
First, I cut down the cup to just the design area.
The next step was to roll each strip of plastic and stick it in the tines of a fork. You could use needle nose pliers to hold it, but I couldn't find mine. My sons have this telescoping handled fork that worked perfectly for this and the tines kept it from unrolling.
With the electric stove burner on high, I held the rolled plastic over the burner, letting the plastic melt. You will have to watch carefully so the plastic doesn't burn, but heats enough to melt the layers and hold them together. The original tutorial I saw used a heat gun. Please be careful with this step. Stoves are hot and I'm relying on everyone to use common sense.
I did this fairly quickly using one cup. If I had taken my time and used more cups, I could have had a less chunky look, but I like how they turned out. I'm going to continue to play with this idea and start using up my Diet Coke cups. It's a prettier way of taking care of the environment!