How do I write a novel in 100 days?

Writing a full-length novel in 100 days is fairly achievable, but it takes a lot of self-determination and discipline. Here are the things you must do;

Write at least 1000 words per day

Write without putting on an editor's hat. Just keep writing. Leave the editing and review for later.

When you get stuck in a scene, part or chapter, indicate that it's a work in progress and move on to another part of the story. Go back later to fill in the details.

You should have 100k words at the end. Now is the time to edit. Delete scenes that don't resonate well with you, add in more details and descriptions, and flesh out the scenes you already have. Go back in to make sure your timeline is consistent. Watch out for minor details such as character descriptions so you don't have a black haired man sporting blonde hair in future chapters.