Got this yarn in a stash swap at the shop. They will be a late Christmas gift for a friend. :)
I basically improvised while trying it on. Cast on 30, did 2x2 ribbing. Noticed I had 4 knit sts together, so I decided that would be the thumb. Increased for the gusset 3 times (two each side of the initially 4 sts), bound off those knit sts when I felt thumb was long enough and joined the rest of the stitches in the round again. Finished in garter stitch because I think ribbing bunches in the palm of the hand sometimes.