I noticed as I was consulting my resources that Knitting Daily and the Yarn Harlot introduce the thrums differently. KD knits the thrum in place of the stitch while YH knits the thrum with the stitch. I chose the YH method arbitrarily. I chose not to do a gusseted thumb because frankly, this is much easier.
So as you can guess, I cast on earlier this week and am about ready to decrease.
Next: the thumb.