Step 1: Add a little bit of oil to taste.
Done.
Take your crappy canned soup and toss in a bit of butter, olive oil, or regular vegetable oil. Sprinkle some sesame oil into your homemade ramen. This is basically the single most important difference between the soup which traumatized you as a child and the inexplicably edible soup you get from restaurants.
Don’t suffer through fall and winter. Soup can be a lazy convenience meal you which can taste good without a lot of effort.
For me what made a huge difference was adding acid, specially for stews. A hearty splash of vinegar or soy sauce while stewing, or even a dash of lime just before serving takes it from “meh” to “seconds please!”.
For sure. Salt, acid, and fat is the trinity to defeat blandness.
A splash of balsamic vinegar (the good stuff) really adds a lot of depth.