In the creative process, the thing I hate more than anything is naming. This includes characters, places, special objects, and even titles. But this post is not about that. It's about geography. The one simply leads into the other.
The reason I hate naming characters is that I find names trivial. They are relatively unique designations, which we use to identify individuals concretely.
To me, my characters are identified by their actions relation to others, or purpose. I use designations in my notes like "boyfriend", "waitress", "hero" and "king". That's who they are to me. I care about the things I actively have them doing, and the rest is fluff that I fill in when I get around to it. I assumed the same was true for geography.
I am working on a fantasy world, which currently is a continent that holds 6 kingdoms. When I finally reached a point that they needed to be named, I made a map of the continent and placed the kingdoms down in a layout I had planned on, I realized that this map basically explained the politics of each kingdom.
When mountains block any travel between two countries, they don't really care about each other politically. When one country is basically in the middle of all the others, it naturally becomes very wealthy from facilitating the trade industry. When one country is so far removed from everyone else, it makes sense that they would hold different policies/beliefs regarding outsiders.
I never gave much thought to the effects geography can have. When I was writing, I treated it the way I treated names: I know what I want my countries to do and I'll worry about the other stuff later. But that isn't right. Geography matters. The absolute and relative locations of places play a very important role in understanding them at their core. In fact, you may find that a lot has to change if your geography does not permit certain actions.