If there's one piece of writing advice that I have seen work consistently for the most writers, I could sum it up as "draft quickly, redraft slowly."
Now you might remember from my "Two types of writers" post that I like to plan and outline before I write. You might also remember that in that post, I said that we don't have to be any one type of writer, and that we're all trying to solve the same problem: that we don't know what our story is until we've written it.
So when I say "draft quickly, redraft slowly," I don't necessarily mean "run headlong into a rough draft" without any planning. Nor do I mean "don't edit at all while you write." What I mean is, don't sweat the imperfections, the unanswered questions that crop up as you write. Take risks, guess, make shit up.
Never write a rough draft scared. Write bad scenes. Write scenes that might entertain only you. Make up facts about your characters that you aren't even sure are true, but might be. Try new things.
There will be plenty of time later to fix mistakes, remove and replace scenes that don't work, and so forth. It might seem quicker if it all comes out perfect the first time, but I have bad news for you: it won't all come out perfect the first time. So all you're doing by being precious in draft one is delaying the time until you 1. can see the whole story; and 2. can get the feedback that will help you know whether your risks are paying off, whether you have the right structure in place, or whether there are significant underlying flaws that need to be addressed. And the more often you encounter those problems after toiling in pursuit of perfection, the more likely you are to retreat into "safe" structures and ways of writing, into comfortable patterns and habits, which may or may not be the best way to tell the specific story you're trying to tell. If you're writing in constant fear that you won't get it right, you might produce something serviceable, but you won't ever take the risks necessary to make it really good.
The key is to mitigate those risks. That's why you work quickly, get feedback early (from trusted sources), and re-write. If something doesn't work structurally, you want to know before you've committed to all of the careful editing of each line.
Once again, everyone has their own process, but you can learn new processes, and I've seen numerous writers, who used to be very precious about getting each line right before submitting a draft, adopt this approach and produce some of their best work as a result. By drafting quickly, they see the whole story faster, and then when they double back to rewrite, they have bring a better perspective on the earlier scenes that makes their rewriting stronger. They have learned things about their characters that they didn't know when they started that they can now layer into the work. They have invented pieces of backstory or lore along the way that can be seeded earlier, making the story as a whole stronger. They can solve structural problems without being so invested in the existing structure that it becomes a struggle to imagine the story differently, or without feeling so personally attached to their perfectly constructed lines that they can't part with them.
I've always been a fast writer, and people often wonder how, and this, combined with a solid, but not exhaustive, scene plan going into writing a draft is how I do it. The scene plan provides a loose blueprint, a guideline for how the drama of the story should ebb and flow, to keep my drafting focused and on target. I don't have to spend much time thinking, when I start to write a scene, about what it's supposed to do in the story. And then I dive in, and I write, and I edit a bit as I go trying to get general character dynamics and scene setting right, but not perfect, and then I move ahead. Only in the next draft will I spend hours laboring over a single scene, and even then I will sometimes draft multiple versions or approaches to the same scene quickly, to allow myself to try out new ideas, before committing to one to revise. The result is that when I hit a challenging section of the work, rather than being stressed about it, I free myself to write bad scenes, and in the process discover what works.w