I made a heated glove liner to address the 3 minor gripes I have with the heated gloves I bought last year. Battery placement on the wrist interfering with glove fit, the heating elements being on the back of the hand, and the glove being a little bulky.
While I was at it I made an Instructable if anyone is interested in how I made them:
https://www.instructables.com/id/Heated-Glove-Liners/
The most expensive part of this project would be the batteries / charger. In my case I can just use the batteries from my other gloves. But without the controller I will have just 1 heat setting. I have a new respect for people that build tutorials, it is fairly time consuming taking pictures while you are doing something, taking notes, editing the images, then creating a coherent set of instructions.