Like many professional endeavors, writing books for a living is something that you must do regularly to see results. It is also something that shows improvement the more you do it well. Since writing is an occupation where you get what you put into it, you have to spend the time to hone your knowledge and skills and then regularly practice them in order to get better. There are more unknown, than known, writers simply because many are not willing to put forth the effort needed to succeed.
Edgar Rice Burroughs summed it up in a statement: