|Warm and cosy, in a nubbly wood/acrylic blend.|
You can't even feel the seams..
I simply cast on between 28 and 36 stitches (depends on your gauge, size of yarn, needle size, etc.) and rib-knit for a few centimeters. Then I continued in stockinette stitch until it was as tall as my tallest (er, middle) finger.
I reduced in the usual way, by knitting two together until I was down to only two stitches and pulling the yarn through to bind them, and then I started sewing down the seam (with the mitt inside-out) until I got to the place where my thumb would start.
I then picked up 5 to 6 (depends on size, again) stitches on one side, knit them back, and picked up 5-6 more on the other. I knit the thumb flat until it was the right length and reduced in the same way I did for the hand.
I sewed the thumb seam on the outside of the thumb (though the mitt was inside out when I did it -- this is important so the seam looks neat).
I continued to sew down to the bottom of the wrist, then turned the mitt right-side out, and voila! A mitten. Then I did it again.