his blog, so sorry that the blog looks like forgotten by the author), I love how he mixes colors!
I was much more free here, did not read the instructions and mixed colors looking at the photos and not reading the mixing recipes.
I can not say what the instructional books are. Are they help or harm or nothing. I think that any type of practice is good for my feel of watercolor and knowledge of technique. I also think that the info gets into the head, boils there and later adds to the understanding of the subject. You can not explain why you do this or that, you just know what to do. Why? Because someday you read something and almost forgot it. Almost.