how to make turkey stock not suck

What do you do to the carcass prior to putting it in the stock pot with water? I ask because I always take a turkey carcass (or chicken also, for that matter) and roast it in the oven at 400F for 30 minutes on a greased sheet pan with quartered onions and carrots prior to putting all of those ingredients, plus a couple of bay leaves, in a stock pot to cook. I use 16 cups = 4 quarts water, bring to a boil, then let simmer, covered, for an hour; after that I let everything cool for 45-60 minutes, skim off any fat on top, strain out the carcass and other solids, and put into storage containers (freezing most of them).

If it's too fatty, refrigerate and let the fat solidify. Or skim as much fat as you can, if you don't have time for the refrigeration.

Add more water if it's too salty. I would also add some carrots, onion, and celery for a little sweetness and some aromatics. I like adding thyme and/or fresh ginger root. A little fresh ground black or white pepper.

Back in March, at the start of SIP in California, I made wontons with a turkey broth. Made the broth with a turkey carcass and the above mentioned aromatics, except thyme. It was such as comforting meal for us.

BTW, ginger in dumplings are a revelation :)