I've heard not to spend too much time on world building. Brandon Sanderson on writingexcuses said to focus on areas of conflict, IIRC.
Rereading your post it sounds like I'm getting confused WB- in Story is what you are talking about. WBiS is spending too much time in story talking about your world. Which KSR does in the mars trilogy but gets away with.
The WB sanderson was talking about was just spending more time building the world than writing your WIP, eg "These noble families way over here are having a Gleph-Guibelline type war and I'm spending two weeks figuring out all the players (ie copying from italian history with the names changed a bit), even though my epic will not reach this part of the globe for four more books." Maybe call this World Building-Game Master, since its the sort thing RPG GMs do.
It seems authors will always have WBGM we don't show. Butcher has all sorts of WBGM planned out eg who gave the werewolf belts to the FBI. But you actually have to make progress on your work in progress, so don't spend to much time on WBGM.
The writing Excuses crew do indeed talk a lot about sources of conflict. Finding the what, where and why of the conflict of the story elements is the way to go.
However, I personally like to compliment this advice because I feel it's incomplete. I like to think about not just what the conflict is in a story but what are the
Isles of Stability.
I think of icebergs on a body of water. Conflict is when two Icebergs rub against eachother. The icebergs themselves are this things in conflict, which are in and of themselves whole objects. Something has to hold these icebergs together otherwise they can't rub against each other.
The WE team focuses a lot of energy on, "Why are people/places/things in the story arguing with each other?" I personally like to think about why People/places/things are not doing that. What keeps the story elements whole?
That's the Isles of Stability.
If you have an Evil Emperor bent on World Domination, why the heck do people follow him? If they are following him because they are afraid of him, why? How do they know? What makes someone put on the Imperial Uniform and swear allegiance to the Emperor?
If you have a bunch of fictional religions in your world, W.E. recommends you find the conflict between them. I recommend finding what brings people to those fictional religions.
A classic piece of character development is what a character wants(his goal) and how that character needs to change to achieve that goal. The Isles of Stability in this case are the Character's goal and why he wants it and why the character keeps pursuing the goal despite the obstacles in his path. When the MC gets knocked down in the ring, why does he get up on count number 7? What keeps the character on his path?
In terms of the Thread Topic of Backstory vs World-building, here's my two cents:
Tell your story in as few words and concepts as possible and gradually add more. The human brain can only have so many ideas in mind at any one time. An audiobook I was listening to (
Your Brain at Work by David Rock) explains this in more detail than I can.
What is the minimum amount of information about the world and/or the back story to understand what's going on?
What are the Isles of Stability and the Conflict between them?
The key goals in regards to presenting world-building and backstory for me at least are images to keep in mind(visual motifs, themes, etc) and what the story is about.
I had an example...but it might give people ideas...like me.
