I attended a Meetup once and one of the topics was world building. The level of detail that went into this one person's world was incredible. His challenge was the story. For me, I had the story but the world was a blank slate. Of course, I knew how to get to the world (via the moon shadows) and I knew the people of that world lived by the sword, but that is all I knew.
What did I do? I started by making some broad decisions such as transportation was in the form of horses and wagons of varying types and styles. When I got to the first scene where I had to describe the buildings and the people of a town, that's when I was forced to deal with the world and it's rules. I asked myself questions like
- Is there any electricity in this world?
- How advanced are they regarding plumbing?
- Does this world have building materials that don't exist in the world of shadows?
- What is the role of the men and women in this world, and does this influence the clothing they wear?
There were other questions. Each time I made a decision, I wrote it down because it became a rule. It meant that, as the story progressed, I needed to shape the scenes to be consistent with my initial broad stroke decisions, as well as the details. Setting basic ground rules about the world helped me design the smaller aspects of the world as I went along.
I also created a map of the lands in the world. I did this simply to save myself from mental fatigue. My characters move around a lot. One day they are heading south, the next day they are heading north. Yikes! Where are they again? I sketched a map and included towns, roads, lakes, and mountains (there are mountains in Luxatra). If I needed them to move from point A to point B, I looked at the map, estimated how far it really was and then how long it would take to get there given their mode of transportation. This part was hard as it influenced the tempo of the story at times.
So, what does all this say about world building? Not a lot. It's just a way of creation. Will I build my next world this way? Yes, however, I probably won't be able to help myself but to look ahead more often, thus painting the world in advance of arriving.