So. I just finished another book. It takes place on a fantasy world, and, like any good writer, I had to create a set of rules and history in which to base my story. In addition to creating races of sentient beings, I had to create rules for magic and laws to govern it, and these regulations had to be consistent and carry their own logic.
But... I didn't.
Sure, sure, that's crazy. I realize that most fantasy writers would be horrified by the thought of going blindly into a new world. BUT I didn't feel blind. I felt determined. I had a destination in mind. I knew the story, and even if the main characters were not human in any way, I still knew which direction their story was heading. In essence, I worked on my plot first, weaving the characters together. When I was finished with my first draft, I had much better idea on how the laws of my new world worked. In fact, I felt better prepared for tidying up the loose corners of the histories and consistencies within the story arc than I did beforehand, because I knew exactly what was going during the story. I also had a lot of fun creating certain names of my characters and locations. In fact, world building at the end of the story-writing process actually worked better for me than doing it beforehand. Not only did I not get so caught up in the details of my world that I did not finish my story, I also felt more in control of what I was creating.
So many times, I meet or talk to aspiring writers who say they've been working on their world for years and are thinking about starting their story. No! No no no. Write the first draft. Write the first draft!!!! Get it on the page. Get something on the page. It can be terrible - it's okay, it's a first draft. No one but you ever needs to see it. But to get better at your story, you need to write your story out. You're flexing a muscle. You can't build it unless you use it. World building is fun and wonderful and I enjoy it - I'm a fantasy writer, of course I do. BUT if never got around to actually building my plots, I'd have no book.
I was once in a writing group that was reviewing a book a few chapters at a time. One of the complaints I most remember was for my repeated typos. I kept telling them, I'm not worried about that right now. First I have to see if this story is working. Why spend time editing if I'm going to erase the whole page at a later date? In addition, I'd already written the first three chapters several times and had yet to go any further. The time was right at that moment. I wasn't going to stop anymore to world build. I was going to finish my story. The rest of it - names, maps, magic - that would come. Some while I was writing, some later on during a research phase. But right then, I wanted the plot done. And it worked. I got through the story and was able to figure out my world and where I was going with my characters much more easily.
So my thought to anyone reading this is, if you are stuck, try letting the world building go for a while and focus on the story. See what happens. It might be a little scary, but... it might also be a little fun.
P.S. I also write super technical science fiction, and in those cases, I absolutely research before, during, and after, as that helps me understand my story better since it's generally based on our current level of technology. But more on that another time...