How do you make Santa boots for dolls?

Hi Marlene, you could make boots from black felt fashioned to the correct size for your dolls, then small amount of fur fabric for a cuff. Here's an article that might help you envision what to do.

https://www.haba.de/en_GB/little-friends/diy-instructions-st-nicholassanta-claus-boots-/e/86ih0

You can use felt . http://allcraftsblogs.com/dolls/santa_and_angel_doll_patterns/santa_and_angel_doll_patterns.html This is for a complete doll but you can get the idea from here.

I would look for doll snow boots (the old fashioned rubber style with the button on the side) and paint them black.

https://www.deviantart.com/scargeear/art/Making-boots-for-BJD-tutorial-265245365

https://www.youtube.com/watch?v=wzeeHWeM8YU