Pickoff most of the turkey meat that is leftover and set it aside.
Break up the turkey carcass so that it will fit in a very large soup pot and place it inside the pot. If you have giblets, throw them in too, except for the liver.
Cover the turkey with water or broth.
Place an unpeeled brown onion or two (whole) in the pot. The peel will give the soup a nice color
Add celery and carrot tops, parsley sprigs, bay leaves, garlic, to the pot and bring to a boil.
Cook down the broth for at least an hour but preferably several hours at a low simmer.
Let the broth cool a bit and strain the liquid into a smaller soup pot to make sure there are no bones in the soup. Use a fat skimmer or just use a spoon to take out any remaining fat.
You will find more meat will come off the bones. You can save some of this to put back in the soup or feed it to your pets. Pets love Thanksgiving too.