I made several from patterns I found on the net.
These I made with my own pattern. I cast on 36 stitches with size 5 needles and knit 2 inches of 2 x 2 ribbing, then change to size 7 needles and knit 3 inches of stockinette, then back to size 5 needles and another inch of 2 x 2 ribbing.
I bind off. I fold the piece right side out and sew the ribbing at the knuckles and the ribbing at the cuff, leaving an opening where the stockinette is. that's where the thumb sticks out. Turn inside out and make another the same. Enjoy!