These thoughts occurred to me as I am currently in the process of writing a book. As I’m a complete amateur writer with no previous book writing experience, take everything I say with a grain of salt.
When writing a non-fiction book, you need to have something to offer to others. You don’t have to be an expert, but you should have experience or special knowledge that most people don’t, and something that others may want to learn from you.
You should start by having a clear idea of one topic that you want to talk about. Don’t try to mix multiple ideas except when you really feel they need to be talked about together.
Then start with why you are talking about this topic. What problem are you trying to solve – what is your “why?” Perhaps offer why you are qualified to be doing this.
Flow on from what you wrote initially. Sentences should lead to sentences. Paragraphs should lead to paragraphs. Chapters should lead to chapters. So the book should write itself. And when you do this right, the readers will feel sucked into the book and find it an enjoyable ride.
You should have an idea of the topics you want to handle. You might talk about what should be done. You might also talk about what should not be done. You may also give examples.
There should be a bringing-together of the information that was laid out, so that readers come away with a solid understanding of the flow that you want your readers to experience.
These are some of the things I noticed reading many good books, dating back all the way from modern times to centuries or millennias back. Hopefully I will be able to incorporate much of it in my own writings.