I used plastic table cloth that we had left after my daughter’s BD. Cut it up in strips and crocheted away while my kid was napping! The bowl is round. For the “puff” stitches on the border I used another plastic strip with more white in it, cut up from grocery bags.

Good tutorial on how to cut the bags - http://www.cocoknits.com/info/tutorials/plasticbagknit.html