To begin with, you need to write. This seems axiomatic because it is. The only way to amass a pile of words into a book is to shovel some every single day. No days off. You have to form this habit; without it you are screwed. I’m going to assume everyone who keeps reading already has this down. If you don’t — you won’t make it. My best advice on how to form this habit is twofold: Get comfortable staring at a blank screen and not writing. This is a skill. If you can not write and avoid filling that time with distractions, you’ll get to the point where you start writing. Open your manuscript and just be with it.