It’s wise to start with the settlement’s location, as this affects everything about it, including layout, climate (and therefore dress), and neighbors, which can include not only other settlements and sovereign powers, but nearby species that live in adjacent terrain. The settlement size, and therefore population, is a second area to consider, as this affects the society and its world view. We might next consider the defense needed due to nearby threats. What it’s known for can either be a starting point or a minor detail we add toward the end of our conception. Above all, start with whatever strikes you as a solid idea you won’t change your mind on later, as this inspiration often colors much else about our invention.