FWIW, what the Stanford Graduate School of Business types found was that when you take a bunch of inherently pretty uncreative people, then try to regiment their creativity with a rigid process, they become even less creative. Gee, ya think? Creativity, by definition, cannot be bounded and contained, and the best creative insights are "bolts from the blue"...
We had a saying in our house we all live by.
Practice makes you mediocre, perfect practice makes you perfect.
And yes, even with creativity.