MRC Halifax
To what extent has the economy of the world been planned out? Obviously, there's a refreshingly fair amount of economic activity happening in the novels, often times helping to move along the story. But to what extent do you have it planned out already vs. "I'll come up with it when I need it."
That is to say do you know that place A sells to place B, but place B has nothing to sell to place A and so sells to place C, which sells to place A, influencing the trade patterns of ships. And what the price of a horse is in A vs. B vs. C., or the price of an inn for the night, or the price of a pair of well made boots. Have you worked out how people are taxed and tithed, how the trade routes flow, how comparatively wealthy people are around the world, etc?
Brandon Sanderson
For a lot of these things I've done some of it, and for others I decide what to do when I need it. One trick in worldbuilding is to focus your attention on the things that are going to be a source of conflict or passion to the characters. It would be very easy to spend twenty years worldbuilding and never writing. So there is a fair bit of both, but most of what I focus my attention on is where is the conflict. Trade deals are a source of conflict, and so where it's a source of conflict to the cultures I have spent more time dealing with it.