I made up my own pattern to test out a cable idea and figured that I’d turn my sample knit into a cup cosy. I’m pretty pleased with the result. I’ve included a seed stitch border on either side of the cable.

Long tail c/o 20 stitches.

Row 1, 3, 5: sl1kw, k1, p1, k1, p3, k6, p3, k1, p1, k1, p1
Row 2, 4, 6: sl1kw, k1, p1, k4, p6, k4, p1, k1, p1

Row 7: sl1kw, k1, p1, k1, p3, sl3cn, p3, k3cn, p3, k1, p1, k1, p1

Rows 2 to 7 form pattern. Repeat until you reach desired length depending on the cup circumference. I bound off once I reached 7.5 inches.
Seam edges.

k = knit
p = purl
sl1kw = slip one stitch knit wise
sl3cn = slip 3 onto cable needle, leave at front of work
k3cn = knit 3 from cable needle