Last minute gift for Connor - to match the balaclava he requested & likes. I just needed to see a pattern for approximate number to CO, etc. That said, I:

CO 30 stitches,
Did 1 x 1 rib, for 12 rounds (2”), because that’s what I used on the hat,
Started gusset increases on round 7 of SS,
Did gusset increases every 3 round because I like a more sloped increase. I started with 2 K2 tog, PM (gusset increases all on same side, at the beginning of the mitt) until I had 10 thumb stitches. On the last increase round, I KFB on the last stitch of the round, then BO the thumb stitches on the next round. After binding off the 10 stitches, I M1 in the next stitch to get back to 30 stitches.
I did a total of 4 rounds of SS, then started ribbing - 6 rounds.

I’m afraid these may be too big. I can squeeze them on my hands.