Does your soup look like a pale parody of restaurant soup?
You may be killing the flavor in the prep stage. Chef Anthony Bourdain wrote in Kitchen Confidential :
"Home cooks underestimate the power of stir-frying. Throwing raw vegetables into water is a crime!"

Mistake 1: Not preparing vegetables properly. Carrots, onions, and celery should be caramelized in a mixture of olive oil and butter.
“The golden crust accounts for 50% of the broth’s flavor,” says chef Pierre Ganio.
Mistake 2: Adding salt at the beginning of cooking. A study in the Journal of Culinary Science found that adding salt before meat is done draws out the juices, making it dry.
“Add salt 10 minutes before the end,” advises chef Marina from the SuperSoup blog.
Mistake 3: Ignoring acid. A drop of lemon juice or balsamic vinegar before serving “revitalizes” the taste. Harvard University scientists explain: acid balances fat and salt by activating receptors.
Amazing lifehack: Add dried mushrooms to the broth. They contain natural glutamate, which enhances umami.
“This is how I save even the most boring soup,” shares chef blogger @UmamiMaster.