Elizabeth discusses a variety of mittens in this chapter of the Knitter's Almanac -- thumbs at the side (thus at first interchangeable for right or left hands), thumbs that fold naturally against the palm, Norwegian-patterns on front and back, and the ones that I knitted this week, mitered ones that shape themselves into a point at the top.
I used two balls of Cleckheaton Machinewash 8 Ply Crepe, in a bright teal green with colored flecks, which I fondly imagine would be lovely against snow, although I don't know if living here in Southern California will give me much chance to find out! The miters, alternating an increase and a decrease, shape the mitten very prettily. At the spot where you want the mitten to curve around the ends of your fingers, you simply eliminate the increases at the sides and continue with the decreases, which pulls the sides of the mitten into a point at the top -- which discovery cheers Elizabeth enormously!
I added one more decrease round at the tip, because it was easier to graft that way, and it made the grafting all of a piece with the line of mitering up the front and back -- thus,
Elizabeth also digresses a little onto the subject of color, with which mittens are an ideal means of experimentation. Do people see the same colors differently, and does this account for the different preferences for the same colors that people have, she wonders. And associations with certain colors can matter enormously -- "For years," she says, "I loathed purple because it was the color of a droopy and voluminous hand-me-down coat I had to wear"! Mittens, since they take so little wool, can be a way to try different colors, or combinations, of course, with little emotional or financial investment!
You snip a stitch where you want the thumb to go, and unravel a bit (I was amazed at how easy this was, after cutting the Aran last January -- I was quite blasé, and snipped without a second thought),
then pick up 15 or so stitches and work the thumb in the round.
I put the thumbs a bit low, I realized afterwards, and would recommend that you judge by the spot where your thumb connects to your palm, not at the bottom of your thumb joint (this part is a little vague in the book). That spot will be at the outside edge of the mitten, keeping in mind that the miter will cause the unravelled row to run downwards at a 45° angle towards the center of the mitten. (You will need to mark the spot at the edge, and then follow that row down to the middle of the miter, because you need to snip in the middle and then use the unravelled ends to reinforce the edges of the hole, as in the photos above.)
I added a bit of length to the thumb to compensate for the smaller gauge of the Cleckheaton, but that was all.
I found that the easiest way of sewing in the ends was in fact to wear the mitten, which gave the odd but amusing sensation of sewing on my own hand!
These are not perfectly anatomically correct mittens, and this is something of a detraction, for it means that the thumb when worn pulls the miter away from its line --
but on the whole, I think that the sheer ease of this pattern is much in its favor.
"Stash them away as they are finished, and when the time comes, next winter, you can deal them out with a liberal hand"!