What I Learned From Writing This Book

What can you learn from finishing a book?  You can learn so much. Did it work? Why were parts hard? Why were parts easy? How come it went out on its own despite the author's best intentions?   These are all the questions you ask when you are done with a book. If you don't then maybe you should. Writing is learning. If you are not paying attention, then you will never get the books right.   For one year, David wrote down what he learned from each of his book projects.
Some of it is stuff he continues to struggle with (like letting the book dictate how long it will be, and not a predisposed number that will make the book long enough) and some are specific for each writing project (like when he realized that his book introductions are dull and he better fix that)  There is a lot to learn. David writes short books, so he was able to share 23 essays about each of the eBooks he put out.  Take some time and learn how David learns from writing and then go out and do it for yourself.
Ask the question, "What did I learn?" You will be a better writer when you do.