I want to love every technique like this (or their more involved cousins like a typography "vertical rhythm" system)... but when it comes time to build sites with some visual and/or layout complexity (for a business client, not a blog that's a relatively simple stream of primarily-text articles), I always wind up with so many exceptions to the rule that I find these catch-all declarations to just be one more thing I'm working around.
For me, the single most useful technique I've discovered in the past few years has been "drop the 'C' in 'CSS'" and instead think in terms of modular components with virtually no cascading or selector nesting. E.g. BEM. Getting over the aesthetic ugliness of "class-itis" in my markup has freed me from a ton of agony trying to reason about why certain elements on the page are being styled a certain way.
For me, the single most useful technique I've discovered in the past few years has been "drop the 'C' in 'CSS'" and instead think in terms of modular components with virtually no cascading or selector nesting. E.g. BEM. Getting over the aesthetic ugliness of "class-itis" in my markup has freed me from a ton of agony trying to reason about why certain elements on the page are being styled a certain way.