When chopping the vegetables, aim for a size that's around 1/2-inch. Smaller chunks will cook faster, if you like softer veggies in your soup. Just make sure to cut all the veggies about the same size, so they cook evenly.
Adding salt at different stages in the cooking process helps build flavor. Instead of just adding salt to the broth, I season the veggies as they're added to the soup.
This soup can be changed depending on what you like and what you have on hand. Choose whatever types of veggies you like best, add pre-cooked pasta or grains if you like, or add more beans.
I like to freeze a big portion of this soup in a gallon Ziploc bag, or smaller portions that can be defrosted for lunch throughout the month.