I have made many of these bowls. It is so easy and addicting! Susan Breier's book, "It's A Wrap" includes loads of photos and information.
I start by organizing my 1/2"-1" fabric strips in bowls. Quilting cottons seem to work the best, cut on the straight of grain. Experiment! You can come up with really neat effects. Try using fabric that you might otherwise think is unattractive.