Some books want to be linear. You get a nice, neat formula that takes you from point A to point B, you may find you have to detour at point C, but whatever. You mostly get to The End without a hitch.
The has never happened to me. My books are archeological digs with millions of bone shards that I have to put together a single piece at a time only to find out that psych! That piece doesn't really go here, it goes way over there.
Here's what I can say about the process, though.
I always have a general idea of the thing I'm digging up. I know the ending. I may not know how I'm going to get there or how I'm going to reconcile beginning to end, but the ending of the book is my starting point. I know where my characters must end up. Then I look for a beginning based on the characters' flaws and/or weaknesses. Some books can be written beginning to end. They are rare for me. Far more often, I write scenes from all over the place. I'm firmly of the opinion that if I don't know what happens next in a story, I move on to where ever I DO know what happens. This is wasteful. I do write scenes I end up not being able to use. One some books, it means overwriting the book to the point that I have two of the thing. It's useful in that I gain insight into what the core conflict of the book is. Eventually. The day comes, however, when I have to take my collection of disparate and oddly jointed scenes, pin them together into a skeleton, sculpt some flesh and features and see what looks back at me.
That's the easy part. Getting the original bones out of the ground, that's hard. Once I have a collection of scenes, I can pin those together with transitional scenes and a the glue of a few sentences about POV character drives. The initial revision pass polishes up the structure, and adds the flesh. It's the developmental editor who really gets me to put the features on the critter. We glue in the glass eyeballs so they stare into you no matter where you go. The copy editor does the airbrushing to make it look like it could move at any second.
Yeah. I far prefer the archeology metaphor to knitting or weaving. Cause, dinosaurs! and I guess I'm still twelve.