Steven Johnson’s book is really a historical one, as in the tag line “The Natural History of Innovation.” The premise is that human and nature innovate in striking similar ways. If we accept that, then we can cultivate innovation by creating the right environment, taking a cue from the nature. He gave many examples, some in nature and some from various societies or the history.
Innovation is done drastically differently as a professional or amateur. Anyone can get struck by a flash of genius can come up with a song, nice poem, great idea, etc. But artists, writers, designer, or some engineers need to innovate as their everyday jobs; they do it very differently. It is a laborious and deliberate process that allows few errors.
The most common method to innovate, by professional and amateurs alike, is to explore the adjacent possibilities. Simply put, by tinkering something in existence already — trying new solutions to old problems or old solutions to new problems. The eureka moment is usually after days, years, or even decades of tinkering, pushing, and try-and-error. As such, to professional innovators, ideas worth little. The skills to turn ideas into working solutions are truly valued.