Step 1: Who do you want to write the book for?
Who do you want to write the book for?
By that, I don't mean the dedication a la "This book is for my grandma."
Rather:
Who is the target group?
The most common mistake is then this answer:
"Everyone".
Sorry to destroy your worldview, but that is the stupidest answer there is to this question.
If you write for everyone, you are writing for no one.
Why?
Very easy:
On the Internet, everyone has a israel telegram screening megaphone.
Social media, YouTube, blogs, e-books: anyone can publish today.
And everyone tries to be as loud and noticeable as possible.
So if you write "for everyone", then you are also competing against "everyone".
In other words:
You simply have no chance.
Furthermore, if you say "everyone", then "nobody" feels addressed.
(That's why, if you need help, you should never shout into the crowd, but point to a person and say: "You with the blue jacket and the red cap, help me.