Don't expect a clear how-to guide. The Fugates wade through the mass of papers Erle Stanley Gardner left and pull out some interesting notions. In a sense, it's the ideas these notions spark in the reader that are important.
Some of the stuff is obvious, but perhaps writers overlook it. For instance, that readers want to escape and so have to be able to identify with the hero/heroine -- remembering that ESG wrote popular fiction.
Other stuff is boiled down in a way that might make sense to you. I liked this:
Purpose encounters Obstacle and creates Conflict.
He also has an interesting take on advertising - see what is being advertised most, what is popular, and write that.