They are very easy to do and look great.
Row 1: Make a circle from 5 chains. Then crochet 2 chain stitch and 15 half double crochet.
Row 2: *Crochet 35 chains and catch them on the first chain of the circle with a slip stitch. Make a slip stitch between the next half double crochet. Crochet 20 chains, then catch them in the same place with a slip stitch. Make a slip stitch between the next half double crochet * Repeat the model between *and* seven times.