How do you go about designing new magic systems? Because that's one of the most amazing things you do.
I've written several essays about this, so if you go to brandonsanderson.com/writing-advice, you'll find my essays on magic systems. Basically, I'm trying to look for something that I can explore in a way I haven't seen people do before. It doesn't have to be a new power, it just has to be a new take on a power that I can explore, that I can have fun with, that I can find some sort of scientific rigor. I like to have this sort of have one foot in science and one foot in superstition. That's what is fun for me in worldbuilding, this idea that-- I often say a lot of the old scientists, like Isaac Newton, believed in alchemy. Like "If only we could figure out..." and they started applying the scientific method to alchemy. Which is so cool! It's like "If we keep trying, we'll eventually figure out how this works." But it doesn't work.
I like this idea of applying the scientific rigor to something superstitious, and finding that it does work, and then what do you do with that. So that's what I'm really looking for, particularly in my epic fantasies. It's also got to be the gee-whiz, the wow, "This is really exciting. This is really interesting."