Hi Nik, good article. After having done nine books, seven published by national publishers (non-fiction) with advances, I have a bit of advice. Outline your book with a sentence for every page in the final version, then write the whole thing without doing any editing at all. By the time you get half way through you'll want to rewrite the first half anyway. Go right to the end without reading or messing with it. You can do it.
And thanks for publishing me when I first stsrted writing on Medium! M