I made a couple hats on my Sentro circular knitting machine. Then, for embellishment, I knit some icord using the Cordy icord maker tool, then wove it in. I then played with another hat a bit more. Here is a video of the first hat (gray/blue). My daughter LOVED the orange one.
Cordy icord tool is available on the kriskrafter.com website. Shipping worldwide and qty discounts.