Salt, Fat, Acid, Heat — Mastering the Elements of Good Cooking is a highly rated cookbook and a limited Netflix series (4 episodes, 1 for each of Salt, Fat, Acid, & Heat) by Samin Nosrat.
But you don't need the book or the show to start making your food more delicious (most of my cookbooks are from America’s Test Kitchen/Cooks Illustrated). It's primarily a framework, so all you need to do is just check whether you've included each in whatever you're making. (I think "Texture" is missing, so I'll run a check for that too, and for whatever reason, I don't think as much about heat as a variable to switch up).
So let's say you were just going to have some rice. You might consider adding salt, but what about butter? or sour cream? what about squeezing some lime on it? 😋
Mashed potatoes? Salt, butter, maybe sour cream (to hit fat + acid), and I'll crumble some salt and vinegar potato chips for more acid and some texture diversity.
Salts (kosher, sea, table, etc.)
Rice wine vinegar
Red wine vinegar
White wine vinegar
Heat & Texture