Of course, you know I’m going to say it really depends. Some people are inspired and have learned to just let the thoughts roll out of their mind untethered and edit it later. Others approach a book with an outline and plan as though they are writing a thesis. Others write when they feel like it and let the content sit for long periods of time and then go back and attack it later. There are no right or wrongs. Every person is unique and every book is different. The one thing in common is that a book is the author’s “baby” and their creation. The author may feel many emotions bringing this into the world and it can raise a myriad of feelings.
Doubt about whether the book, style, content, etc. is good enough is a big one. It is rare to meet an author that doesn’t have some type of concern about publishing a book. Is it going to sell? Will I put all this work into something no one has an interest in reading? Can I make some money? How much money? What will my family and friends say? Am I good enough?
The point in writing a book is CREATING! You get to make your thoughts visible to others. Is writing something you feel called to do? Must do for your career? Want to do to finally say you’ve done it? Have an idea that is leaping out? Whatever the reason, please take the pressure you are putting on yourself out of the equation and try to enjoy the process. There are editors and publishers and graphic artists to help. Your job is just to CREATE!