This pattern uses a basketweave, and it’s made to fit around all Starbucks cup.its a free pattern too. - Warm and Toasty - Crocheted Mug Cozies - by One Dog Woof
motleymakery: “Vintage Crocheted Watermelon Pot Holders, via Martha Stewart. Martha’s link is broken, but here are a few free patterns: moms love of crochet free vintage crochet art threads crochet.
Cup warmer and coaster
Cream and pink crochet mug cozy
cute idea - has pattern for sale but great inspiration for experienced crocheters