Writing is quite a personal thing, with authors each having their own idiosyncrasies and quirks to help them imagine and get the words on the page. Books may start in a dream, but like anything worth doing, take days that may stretch into years to get into the hands of a reader.
World building will also vary depending on the writer. A writer may be an intense plotter, with character sketches and chapters planned out well before any writing happens. For many, the knowing of the plot in some detail helps them write faster, and with less chance of writing into a blind corner, where the plot fails due to some unforeseen event. For plotters, there is a lot of advice in the form of character interviews, plot outlines, the development of the story arcs etc. In some ways it is all too easy to keep developing the story and plot without really getting to the actual writing of the story.
In the same way, world building from the outside in, or building the world first is quite similar. For fantasy, scifi and historical fiction, much research can be done via the internet, facebook groups and reading, as well as sparking your own imagination. The minute details of a world can be time consuming, and perhaps somewhat self-defeating if there is a whole lot of history or culture that is created, yet not used in the book. Tolkien is a prime example of this, with pages of details on the world and history of middle earth. There would be many writers out there with a similar amount of detail on their worlds.
So nutting out fine details can be a good thing and also a bad thing. In terms of time, you can only pry so much out of the day, and in the end, getting a book finished is a very satisfying thing. Are those minute details really essential? Often readers will skip too much detailed description, or can imagine it themselves. It makes for a slow read if there are pages of stuff about some war three hundred years ago. That’s nice, but you still made it up, so you really need to make people care about it as much as you do. As fantasy, scifi and historical are firmly based in a world, readers will accept and enjoy more detail than many genres, but you do risk making the pace glacial. With attentions spans supposed to be declining, the ability to get away with info dumps on the history of your world is fading.
A detailed world does have many good points however. JK Rowling used hints to past events, piquing audience curiosity and paving the way for spinoff books and movies. Reading a small detail in a book is a rare treat for some readers who cherish little nuggets of information about for instance the taste of chickweed in a Celtic salad, or how heavy a sodden woollen cloak feels, or the flavour of herbs in mead. Devoted readers will want more and more detail, so you will be able to provide that! There is also the sense of security in writing from a point of complete familiarity with the world – you know the feel of the streets, the smell of the tavern or the layout of the controls in the rocket. Remember Samuel Vimes in Terry Pratchett works, where his cheap cardboard soled shoes let him feel the ground, and identify the street by the types of paving? Not only is this a marvellous example of world building detail, it also pointed out social and economic issues, as well as personal memories, financial issues and the character of Vimes himself. A lot of things flower in that description, and one is never bogged down in the details that Pratchett would have had in his head.
The other type of writing and world building is from the inside out. This is where the plot and characters are foremost in the authors mind. This is possibly a technique favoured by writers who call themselves pantsters, in that they write without plans, letting the characters take them along for the ride. Fast paced authors like Matthew Reilly skimp on the detail, preferring to use drawings and the reader’s imagination to flesh out the world. However the use of description is a popular tool for pacing, where a bit of detail can be used to slow the pace and let the reader catch their breath. Michael Crichton balanced it well in novels like Jurassic Park and Timeline, where the world details where needed, but the action never really slowed, but punched through the scene description.
The finer details may be added in during the editing stage. This avoids any slowing down of the writing or distraction of the process of creation. Notes in another file, or *** markers and a note in brackets in the text will aid in later editing. The trouble with this may be that the imagination rides roughshod over facts, and this may cause problems later on.
As each writer is different, so too will the degrees of world building differ. A read of a science magazine may spark a story idea, or a vaguely remembered fact will send you delving into research. Some will need a lot of detail to start, others require very little. Others will write and research at the same time, using new research to create new plot twists or character quirks.
One final thing is worth mentioning. It is worth recording your research sources. Firstly so you can check your memory, but also to acknowledge references to avoid any plagiarism accusations. In these days of ready access to google, readers may easily check a fact, and an incorrect one can make one doubt the whole book. Yes it’s made up, but people do still get annoyed by obviously incorrect details, and they won’t hesitate to tell you so in reviews.