Many worldbuilding blogs and guides that I’ve been seeing lately start with story. They tailor the world to the story that the writer wants to create. This is, of course, a valid and potentially useful method, but not my usual choice (although I did, once, write a novella before creating the world in which it was set).
There are probably almost as many methods of worldbuilding as there are writers, especially when we’re talking about starting the process. Tolkien, for instance, started with languages. As a philologist, he created numerous fictional languages for fun. Then he set about building a world of people who spoke them. Brandon Sanderson says he created one world, in part, because of a magic system that began to develop in his mind during a trip to South Korea. Michael Scott began world building, he says, with a visit to Nicholas Flamel’s home in Paris and the story grew from there.
I tend to start with a bit of inspiration. A group or organization, a place, or (until recently) a magic system pops into my head, usually half formed. Then I start building outward to create the world the group, place, or system calls home. I suppose, in a way, I see the fictional world less as a place to set a story and more as a place to find many stories. In each case, I’ve tried limiting myself to a small location before. But, I always start thinking: What’s beyond the walls? A city (a forest)? Ok, what’s beyond the city (the forest)? A province? A nation? Many nations? A world? Other dimensions? Then things inevitably snowball. I think it may be too much history or the continual reminder that nothing exists in a cultural, geographical, or historical vacuum, there’s always something larger beyond it.