(Game of Thrones spoilers)

As a send off to promote the purpose of this thread, I'd like to describe my personal writing method, which is basically the Snowflake Effect.

How To Write A Novel Using The Snowflake Method

As a fantasy writer creating a brand new world and aspiring to create a series, my first step is a sentence that describes the subject and the subject's inevitable outcome. To use Game of Thrones, the heading is, "The Warden of the North is killed by choosing honor over the realistic intrigue of the Capital when the King names him his first counselor" or something like that. However you would write it, keep in mind the detail starts from the end. The method works from the back, forwards, in the sense that the protagonist's character arc is dependent on their final outcome by the story's end. From this sentence, I would then devise a paragraph and from that paragraph, a page, and from each paragraph in that page, another page. Between each step, I would also expand the character bios. Character biographies and lore can enable one to circumvent writer's block by filling in aspects of the story, there's no rule to which aspect to develop first, one fleshes out the story as necessary. Eventually, you land at a scene-by-scene outline of your story.