These were hooked in Vinnis Nikkim Colours [midnight] and Elle Cotton On - Seriously Chunky in single crochet spirals. I smell a dinner party!
CREATING A FLAT CIRCLE:
Single Crochet [sc] : Start with 6 sc and increase 6 sc in each round so that the total stitch count in each round is a multiple of 6
Half Double Crochet [hdc] : With hdc it is a multiple of 8
Double Crochet [dc] : Multiple of 12
See Cara Medus for tips on how to crochet a perfect round circle without visible corners and seams.