Just remember some basics when creating a soup.
*Unless it's onion soup, onions should be added early. Sauteed onions are best, otherwise mince the onions well so they cook down and become part of the overall flavor.
*Butter scorches easily so use low heat. If you can't wait, margarine is better than burned butter.
*Add veggies based on two things: strength of flavor and time needed to cook. Potatoes are added last because they'll turn to starch and thicken soups prematurely. Add the hardest veggies like carrots first so they will have time to cook.
*Add spice throughout. Garlic powder should never be used when fresh is available. Ready minced garlic in 16oz jars cost less than $5 and saves so much time. Garlic should be added early and added only at the end in small amounts if you feel it needs it. Allow 15 minutes to cook if added late. Spices complement each other. Fresh and dry spice can taste very different and the amount you choose should be altered accordingly. Salt and salty veggies like tomatoes (canned) should be added last.
*Puree veggies to change the texture and flavor. Canned tomatoes are an excellent example. Diced the flavor is not as shared through the soup as pureed tomatoes.
*Looking at numerous soup recipes will give you a good idea about complementary spices and vegetables.