I used a double strand of yarn, the P/11.5mm hook from my Crystalites set, and the extended double crochet stitch. This is a pattern that is only 2 alternating rows and grows very quickly.
I used both the Red Heart Stripes and the Red Heart Super Saver, but any combination of yarns will do. I also have a photo tutorial of how to do the extended double crochet on my pattern page.