(Or fingerless gloves, or glovelets, or whatever you want to call them)
I made my first pair of these two years ago because (1) I had a bunch of holey old socks that I was rather fond of and (2) my hands are always cold. Most of the hand/armwarmers I see in stores barely even cover the entire palm, and many of the models with separate finger holes also don’t cover much of the fingers. To my mind this defeats the purpose of keeping your hands warm while still being able to type/write/turn pages. Here is a tutorial for making your old socks into basic hand warmers. It requires only rudimentary sewing skills (because that’s what I have), and can be adjusted to cover as much of your hands as you like.
First, wash your old socks. They are probably gross. In fact, light-coloured socks have probably become stained from your shoes—you should probably just use them as rags. Black socks, as the Girl Guide song goes, never get dirty.
Cut the toes off said socks. If there are holes near the toes, make sure to cut off the part with the holes! Try to cut each sock at roughly the same point. (If they end up being slightly different sizes, start working on the smaller one first, then cut the larger one to match it.)
Turn the first sock inside out, then turn down the cut edge about 1 cm and pin it in place. Sew this cut edge down – I used a basic running stitch because, as I said, I’m barely capable of sewing. But you could also backstitch or properly hem it if you are better at sewing/more patient than I am. Make sure you aren’t pulling the thread too tight, like a drawstring, or it could end up ripping when you wear it.
Turn the sock right side out again and put it on your hand (as you would wear the finished hand warmer) to determine where to cut the hole for the thumb. It will work best if the heel of the sock is on the thumb side. (If your sock, unlike the one in the pictures, has holes in the heel area, you can use the heel hole for the thumb, sew it up, or patch it over.) Remove the sock and cut a slit where the thumb will go. The length will depend on how big your thumb is, so start with a small-ish (1.5 cm) hole and try it on. Once you’ve cut the thumb hole, turn the sock inside out again and finish it with a buttonhole stitch (or, if you’re me, a loose and sloppy approximation thereof) to keep it from fraying.
This completes one hand warmer. Line up the second sock with the already-sewed one to get them the same size (and the thumb hole in the same position), then repeat the above with sock #2.