This is a few days old, but I've been wanting to link to it. Total Dick-Head quotes PKD reciting his "formula" for a novel in a letter to a friend. This is amazing, because most people out there (myself included), would call PKD the least "formulaic" writer you could read.
I like this, though, because it showed the professional side of the author. PKD is the Samuel Coleridge of the science fiction world, his great ideas and brilliant writing overshadowed by stories of his drug abuse. But he was a pro, and like anyone who gets the job done, he had a system. He didn't just pop back a handful of reds and let otherworldly genius flow through his typewriter.
It's yet another example of how working within certain boundaries can expand rather than limit an artist's freedom.