Just using leftover yarn, vanilla mitts with stripes.

Cast on 36, 2x2 (or 1x1) for 16 rounds. 4 rounds plain, then thumb increases to 13 sts, put on holder.
Knit plain to 44 rounds, 2x2 rib 8 rounds.
Thumb-pick up 3 additional stitches, then knit 2x2 for 8 rounds.