I got some turkey necks and wings at Reading Terminal Market, and roasted them along with carrots, onions, and celery for about 2 hours at 325°F (along with a few turkey thighs -- more on that later). I put the roasted meat and veggies into a big 12-qt stockpot, and added a roasted chicken carcass that I had in the fridge from dinner the other night, and a bone from a recent pork shoulder roast that I had saved and popped into the freezer.
Covered everything with water, brought the pot to a boil, lowered it to a simmer, and let the stock simmer gently for about 3 hours.
Discarded all the bones (not much in the way of meat to retain), and let the stock cool fully.
Now THAT'S good stock -- jiggly when cold, full of gelatin, which adds considerably heft and substance to a stock.