A dish can have all the right ingredients and still taste flat. Salt reveals flavour, acid brings freshness, a small amount of sweetness softens bitterness, and chilli adds warmth rather than flavour on its own.
Adjust one element at a time. Taste a complete spoonful, add a small measured amount, stir and taste again. Lemon added at the end often wakes up a stew or curry more effectively than extra salt.
Balance is not a single formula. It is the point where no one taste shouts louder than the food itself.