While I doubt many of us will ever reach the detail of Tolkien, I find world building an exciting part of writing and often surprise myself with the detail that goes into it that no one will ever know abut because it doesn’t make it into the book.
A few examples: Phoenix serves 4 meals a day rather than the traditional three (in the US at least) because smaller portions over the day reduces over eating and obesity. Both Ana and Alaya are control freaks and would go into this level of detail for something they care about as much as the orphanage.
The U-turn lane. Nevaeh, the capital, has U-turn lanes. Having just test driven a car and missed several exits resulting in three U-turns to get back to the dealership, I was once again grateful for U-turn lanes. For those of you who do not live in Texas, a U-turn lane is a designated lane to the far left of the access road to the highway whose sole purpose is for people to get off the highway and avoid two red lights otherwise required for left turning and going back down the opposite direction on the highway. They didn’t have these U-turn lanes in Kansas City where I went to college, and boy did I get lost. GPS is a wonderful, life saving invention, without which I would be unable to drive.
How do you build the world for your stories? Do you write it down or is it all in your head? How do you decide what makes it into your book and which parts only you will ever know?