Being interruptable and having an interruptable mindset is the most amazing thing in the world.
I was about to make my own handwarmers after making a Christmas present for a friend, and was interrupted by someone sitting next to me on the bus. She had been reading a book, but when I pulled out my crochet hook and started to count out stitches on an old pair of handwarmers, she took notice and nudged me. Maybe twice. I don't think I noticed the first time. LOL. Yes, I can be that oblivious. But I'm glad that I perked up and started talking with her. It was a delightful conversation.
She asked what I had been making, and I told her. Then I started to tell her how to make them. It was as I was telling her how to make them that I realized that I should make out a pattern for them. So here's the pattern, with an example amount of stitches.
CROCHET HAND WARMERSOfficially, you chain however many that you need that runs around the circumference of your hand by the widest part of your knuckles. If you like your gloves to fit loosely, then add a couple stitches. If you like your gloves to fit snugly, then just leave it.
You need to have an odd amount of stitches. This is important to the fit of the handwarmer.
For example, 31. That's the amount of that I'm going to use for the example because of the material and size of yarn that I chose. Now on to the pattern. Comment if you don't understand a step and I'll explain what I mean.
For this particular handwamer set (which is a set that I'm making for myself), I'm using Patons Classic Wool in Wedgewood (color 77011, dye lot 244077). I'm using a 3.75mm hook, US size F/5, instead of the recommended size of a 5mm hook (US H/8). That creates a tighter stitch, giving it a more delicate look while cutting drafts down.
If you're doing this for your first time project, I'd suggest using a US size H/8 and any normal yarn. Disregard the recommended size that it says on the skein if it's Red Heart Supersaver No Dye Lot or something comparable to that. Use worsted medium yarn.
Here we go!
STEP ONE:Ch 31, then ch 1 and sc in stitch 31. sc the remaining 30 stitches. Ch 1, turn, sc next row.
Continue until 7 rows are complete.
(I continued on past the 7 rows because the smaller hook gave me smaller rows, and I wanted to have the handwarmer come up over my knuckles.)
STEP TWO:Ch 2, turn and dc 15. Ch 1 and sc the next row. Repeat this step two more times.
STEP THREE:Ch 2, skip one stitch, and dc the remaining 14 stitches. Ch 2, skip a stitch, dc 13. Ch 2, dc 12. Final row: ch 2, dc 11. Finish. This is the cuff of the handwarmer. You now have an L-shaped piece of work. (With mine, I'm extending the cuff so that it can go up the sleeve of whatever I'm wearing, keeping out any drafts. I did seven rows instead of the three I normally do.)
STEP FOUR:On the 7th row, where you did the 15 double crochet stitches on one side, tie in on the 17th stitch. What you'll be looking at is in the following picture:

Sc to the end of the row, ch 1, turn, sc back 15 stitches. Continue until you have 9 rows. (If you want to have longer palm and the back of hand, then measure accordingly. For every row of dc, you have to have two rows of sc. So for three sets of the dc and sc as I demonstrated, that's nine sc rows. Four sets is 12 sc rows on the palm. Which is also what I did for my current handwarmer.)
STEP FIVE:Repeat Step Three. (Disregard the length in the picture. Remember that what I'm working on right now is my own set of handwarmers.)
STEP SIX:Match up the sides. Sew together the outer sides of the handwarmer in whatever way you feel like. For the middle, sew up ONLY the cuff, which is the final four rows. Finish.
The final product that you will do is reflected in the first picture, where you see two of them tied together.
You now have your handwarmer! Repeat the process to make the second one, but be careful! Remember that the side that has more single crochet is the palm of the handwarmer. Sew accordingly. Remember that you sew things inside out.
Comment with a link to a picture of the finished product! I can't wait to see how yours came out! Please feel free to expand upon this pattern.
(PS: Mine fit FANTASTICALLY! I just finished one, and everything about the fit is perfect.)