I often tend to ignore these sorts of principles and lots of "rules of thumb."
I'm more often going to just feel out if I'm having fun or not and then analyze the why itself.
It's much more effective to only focus on analyzing what you can know rather than worry about what cannot be known. To bring the unknown into the known requires blind experimentation or educated guessing, and once you do it becomes a known that can be analyzed.
Rather than worrying about vague notions of ratios, I just feel out what is fun and dissect why I'm having fun with it, and vice versa.