I like to keep soups simple, but there are many things you can do to add additional flavor to soup! Add dried herbs while the soup is simmering, like parsley, thyme, rosemary, and oregano. Add fresh herbs just before serving. You could also simmer with a parmesan rind, just remove it before serving. A splash of vinegar or squeeze of lemon juice will brighten up the flavor. Seasoning with more salt and pepper will also enhance the flavor of your soup.