Unexpected World Building

The last couple of days of world building for my books have been interesting. It's always incredible all the different parts of world building that need to be addressed and some things I simply hadn't thought about before. I've run into a lot of those with the most recent book I've been writing. In the book, the main character is a human adopted by dragons and so I've needed to determine parts of dragon and Guardian culture that are very specific. For example, today I realized that that if a human girl was raised by dragons in my world, a first period would come as quite a surprise. 

World building is one of my favorite parts. I've found that I've enjoyed it more and more as I've run into hurdles in books I've written and had to solve them. Solving those hurdles than makes the next book more realistic because a piece of a big world has been filled in and can be used. With the book I'm writing now, it's been nice because a girl being raised as a dragon would receive history lessons and be expected to know facts that make it so I can reference dragons and humans in prior books.

Recently, I've been watching Lord of the Rings: Rings of Power and am constantly reminded how much world building Tolkien did. I also think a lot of Terry Pratchett, J.K. Rowling, and Terry Brooks. They all have crafted such vast and incredible worlds. I need to read more carefully to think about different world building things my writing needs. It's an exciting and intimidating endeavor. 

What are some things you do to help with world building? Who are some authors you've read that do great world building?