@JessMahler
I don't know if I have that one favorite part. I love history and love to have it come alive in my books. It's only the framework for my actual story, but it always feels a little like time-travel to immerse myself in that.
Fantasy on the other hand is freedom. I can make up all the rules which I also enjoy.
I guess in both cases it's when the words start to flow and my fingers can hardly keep up.
When I'm in so deep that everything else just fades.