Just about every single writing technique or rule has exceptions. None are inviolable. Except for one.
It's a rule so important that I tell my students to tattoo it on the insides of their eyelids if they have to, and I express it using coarse language to make sure they will always remember it. A rule so impactful that it can ensure that your writing might not be good on a given day, but it will never be mediocre. In over 30 years of writing and over 20 years of writing professionally, it remains in my mind the first rule, and the only inviolable rule. It is rule #1.
To talk about this rule, I need to tell a story about my favourite author, Harlan Ellison (who, as far as I know, at the time of his death was the most decorated author in the English language).
Harlan Ellison was teaching at a Clarion writer's workshop one year, and he handed his class an assignment: write a story about where the lost things go.
The class went away and wrote their stories. They all wrote about socks disappearing, gnomes stealing nick-knacks and the like, and then handed their stories in. Ellison read them, and flunked the entire class. Not a single pass among them.
When he took up the assignment the next day, he ran the class over the coals. Who gives a damn about nick-knacks, or socks, he demanded. Nobody cares about the irrelevant, or trivial. What about HOPES? What about DREAMS? What about that one chance you had at true love, and you missed it? THAT is what you need to write about - those things that are important and always worth caring about.
Rule #1: ALWAYS WRITE ABOUT THE IMPORTANT SHIT.