I know that there is a 'base' you can make for cream soups. Something like butter, flour, milk and veg/chick broth.
Mushroom Soup:
8oz Mushrooms -chopped, diced or sliced
1/4 C Onions -chopped
1 Clove garlic -minced
2 T Butter
2 C Vegetable or Chicken broth
3 T Flour
1/4 t Nutmeg
1 C evaporated milk or light cream
Saute -butter, onions, mushrooms, garlic. Add in 2 T flour and broth, stir and heat until thickened. Add in additional flour, cream. Add all together. Salt/pepper to taste.
I like homemade soups...mmmmm.....my fav is homemade tomato. :)