I get asked “How do you write? Where do you come up with this stuff?” I don’t know how it works for others, but for me it’s like pulling on a strand. I get some basic idea of a story, when it takes place, what are the underlying themes. I would start reading, learning more a particular event or time period or technology. This leads to something else, some other topic. I think it’s important to let yourself wander around, hitting dead ends until something starts feeling right. To quote Bilbo Baggins “It’s a dangerous business, Frodo, going out your door. You step onto the road, and if you don’t keep your feet, there’s no knowing where you might be swept off to.” Well, sometimes you just have to let yourself be swept into the story and it’ll find you.