Here is a list of some things which work super in "Put-everything-you-have-in-a-pot Soup":
I encourage you to experiment with rice and pastas, but keep in mind that these may get soggy. Also try adding eggs or meats,
As far as spices or flavourings go, you can put every spice you have in there, too. Mix it up depending on your tastes. Personally, I like:
-basil/other itallian seasonings
-red pepper flakes
-cumin/other curry spices
-lemon or lime juice or zest
-for a little something different, try nutmeg, cinnamon, fennel, or whatever you have handy!
As a base, it is great if you have soup stock or bouillon cubes available. It adds a little something extra if you add milk, cream or coconut milk to the soup. An excellent combination is coconut milk, curry spices, jalapeno, and lime.
Begin by frying the garlic, onions, leeks in some oil or butter in a large soup pan. Add some spices and stir fry it for a bit, and add the other vegetables you are putting in.
After a couple minutes, cover the vegetables with water/ vegetable stock. If you don't have stock, you may just add more spices.
Let this come to a boil, then turn down heat to simmer and cover for about an hour. Feel free to taste in between and add things as necessary. If using milk/cream, add this a bit later and do not boil once it is added.
Once the soup is done, you may opt to thicken it into a stew by adding corn starch (dissolve corn starch in cold water before adding to the soup). Another option is to blend the soup in a blender for a creamier texture.
Option three: Just eat it! And enjoy. You can freeze leftovers in single-sized portions and save them for a cold, snowy day.