I really do swear by this $17 electric hand warmer. Plus, its cute.

We all know someone who always complains about how cold it is. Maybe you are that person.
Then allow me to make your fall and winter a little more enjoyable. I've been buying these cute electric hand warmers as Christmas gifts for years. They're basically the perfect stocking stuffer. Even at full price, they cost less than $30. I first bought the Orastone Electric Hand Warmer for my long-time partner, who struggles with always-being-cold syndrome, a very serious and under-studied medical phenomenon.
She loved it, using it every day for several winters before its battery finally gave out. Ever since, I've been buying them for friends, family, and under-$25 White Elephant gift exchanges, and they're always a hit. Most electric hand warmers work just fine, but are pretty ugly. The Orastone is the rare hand warmer that's actually cute, and it comes with a lanyard you can wrap around your glove-covered hands.
While it comes in a few different styles, this geometric-print version is on sale at Amazon for just $17.99, down from its regular retail price of $29.99. (Per Camelcamelcamel, its typical price is usually $23.99, so this is a genuine discount.)
There's not much else to say about this one. It's cute, it's warm, and it works. Oh — and it also has a flashlight, FWIW. In my experience, you'll get at least two winters' worth of warm and toasty hands out of this little gadget, and that's a fair deal for the price.