Garnish with a bit of powdered-style Parmesan cheese if desired. This type of cheese is perfect for soups since it dissolves instantly giving the soup a bit of creaminess and salty flavor.
Don't be too concerned with exact measures for this recipe, its all about how you want the soup to taste (I promise you can't mess it up!). For a bigger batch of soup, add more broth. For a thicker tomatoey tasting soup, use the biggest size of tomato sauce you can find at your grocery store (28oz?), or use only 8 oz for a thinner more beefy tasting soup. Same goes for diced tomatoes, use a large can if you like lots of tomatoes (28oz), or less - it's all up to you. Just taste as you go and adjust the flavorings accordingly.