The idea of the book is now firmly set in my mind, after several days of deep thought about it.
I started writing, and it is the first time I've written for three consecutive days without interruption. After reading The 38 Most Common Fiction Writing Mistakes, I can tell you that the best advice found there is to Keep Writing, always moving forward.
In my previous writing projects I kept revising and editing on the fly, which really took away from my ability to generate new material. This time, I'm focusing on writing, leaving the process of self-editing to the time when the first draft is complete.
Being able to just write free me from worrying about the end result, and lets me focus on the plot, the story and the way things move forward in my story.
I plan to do some more reading about the Art of Being a Writer. There are many good books out there, but the The 38 Most Common Fiction Writing Mistakes is definitely worth reading. It presents 38 "don'ts" with good reasoning and good advice on how to avoid those pitfalls.
For now, I simply concentrate on that one advice - keep moving forward!