My Badlands Mitts are knit top-down in order to use up every bit of your leftover yarn. The thumbs are knit separately and later joined to the body of the hand in the same manner that you would join the sleeves of a raglan or yoked sweater when knitting from the bottom-up. This tutorial will walk you through joining the thumb and hand of a top-down fingerless mitt.
The pictures in this tutorial show the thumb and hand pieces being joined via magic loop, but it works the same on double pointed needles as well. If you are working with dpns arrange the stitches of the hand so that the end of round falls in between two needles.
Place the thumb stitches on a single double pointed needle. You will be working the thumb stitches with the Right Side facing you.
This is what your thumb will look like from the Right Side.
And this is the view from the Wrong Side. Don't worry about a gap. We'll take care of that later.
Holding the needle with the thumb stitches in your left hand and the needle with the hand stitches you’ve just worked in your right, place a marker and begin to work across the thumb stitches in p1, k1 ribbing. Don’t forget to create a stitch by knitting into the front and back of the last thumb stitch.
Once you’ve worked across all the thumb stitches place another marker. You can go ahead and join the last thumb stitch to the hand stitches being held on the next needle at this point, but you will get a better join if you redistribute the thumb stitches onto two needles first, with the last half being placed on the new right hand needle as has been done in the photo below.
There you have it: part of a mitt to fit a hand with a thumb. There will be a hole at the top of the thumb where it joins to the hand--you will sew that shut at the end.