said I can only tell my method.
Basically, I write down all my ideas for the book. Then I plan in detail.
I take a piece of A4 per scene and write (by hand) what will happen, who will be the POV character, where it will be set etc
Sometimes there are only a few lines...X pov. He meets Y, sometimes the page is bursting with dialogue and detail and themes and sub plots.
This stage can take weeks.
When I'm done I start writing it up.
And yes, I do write it in order. However, if I get to a scene sparse on detail and I still can't see it or feel it, I just type what's on the scene plan and move on.
I find waiting for inspiration a complete waste of time. Panic just sets in.
If, snippets for other scenes come to me out of order, I scribble them down on my hand written scene plan and include them when I get to that scene. If they are for a scene that has already been written, I just make a note and reassess whether they are still a good idea on the rewrite...again this saves the endless going back and improving that so many writers get stuck on.
Forward motion is my watch word.
Now, plenty of writers work differently I'm sure. But this definitely works for me.
In seven years, I've written six books, two radio plays and endless journo articles.
Prolific is my middle name.