Longest. Entry. Ever.
Most writers at some point early on in their creative efforts, spend a lot of time angsting about whether they're writing the "right way." And if you happen to pick up a how-to book about writing, or attend a writing workshop, you will probably have your angst amplified by more experienced writers insisting that this or that is the proper way to write a book. Add to that the fact that writing a novel is an incredibly difficult and organic and confusing process that boggles even the sharpest minds, and you have a recipe for wanting to find the Right Way and cling desperately to it.
So here is the big secret of the writing process: whatever you do that works for you, keep doing it, and whatever doesn't work for you, don't do it.
Whew. There. The secret is out. Aren't you glad I enlightened you? What? You're still confused? (Don't be. It's as simple as it sounds.)
I actually believe there is great value in writers talking to each other about their processes, comparing notes, etc. Listening to how other writers write can give us clues about what we might or might not find useful.
It only becomes a problem when you let it convince you that because one successful writer writes for 8 hours each day, 5 days a week, always creates an extensive outline at the start, and never, ever suffers from writer's block, then you are simply fucked and will never make it as a writer. Or maybe your favorite author writes really fast, like 20 pages a day, and you are slow as molasses, and this leads you to suspect you should go ahead and take that assistant manager job at Walmart.
Everyone's writing process is unique, much like any other personality quirk, but it's not a set of rules for anyone else to follow. Just listen, and consider, and maybe once in a while you'll pick up something that helps you along your own path. Or maybe you'll just get a little sense of confirmation that you're not crazy after all for only being able to write from midnight until dawn, and only while downing espresso with Nirvana music playing in the background.
Also consider that at different learning stages, your process likely will need to evolve a little, and you should let it. The more flexible you can be about your process, the more work you'll probably get done.
My writing process is weird enough that it will probably make you all feel sane and normal, so I will share it. I tend to write in mad bursts, with dormant periods in between during which I like to think my brain is resting and preparing for the next writing frenzy. The closer my deadlines get, the faster I write.
I don't have a favorite time of day or place to write. Usually, "whenever I'm awake" will do, and I like to write in bed but will work anywhere that isn't too noisy. But since I have kids, I usually try to get all my writing done while they are in school. If I need to work more because of a deadline, I will write anywhere and at any time, and I occasionally pull all-nighters if I have to (but I try hard to avoid this, because it sucks).
I write most of my scenes totally out of order, just writing them as they come to me, and then moving on and writing another and another until I have what I can only hope is something resembling a coherent story (but sometimes not). Then once I can't think of any more scenes to write (this usually happens when I'm 50-100 pages short of a complete novel), I stop and put everything in chronological order.
After that, I have to fill in all the stuff that's missing, delete the repetitive stuff, connect scenes together and/or set them up, fix the continuity problems created by writing out of order, and format the story in chapters.
Because I'm usually writing books that I've sold on proposal (first three chapters and synopsis), I have the synopsis as a rough guideline of how the story should go. Sometimes I follow it, and sometimes my final story doesn't much resemble the original plan.
One of the first scenes I write after I've finished the three chapters for a proposal, is the final scene of the book. Having that scene gives me a destination, and my final scene usually doesn't change once I've written the rest of the book. I might need to fill in some details, but that's all.
Is this how you should write your book? Probably not. Does it make your approach any less valid? No way. But maybe the valuable thing you can take from hearing my process is to consider how your brain works and tweak your own writing habits accordingly if you're finding yourself frustrated.
I'm not a linear thinker, and I consider my writing process sort of circular. The story usually ends in a similar place as where it started, only the characters have been transformed in some way by their experiences. If you are struggling with getting a book done, it might help to figure out if you are a linear or non-linear thinker. Do you tend to move logically from point A to B to C, or do you jump around a lot and consider point Q before you can understand point D?
Linear thinkers generally need to write their stories on a logical timeline, starting with chapter one and moving along through the story as a reader would read it. Non-linear thinkers sometimes might find more creative synergy in writing whatever scene they feel like working on, regardless of timeline.
So let's compare notes here. What's your process?