When I was cooking a lot of duck in December, I saved the bones and scraps, wrapped them tightly, and threw them in the freezer. Well, it was time to make some room, so I spent about seven hours slowly simmering the scraps, the standard roasted vegetables, filtered water, peppercorns, bouquet garni, etc. Skimming, then straining towards the end... A long process, but it's worth it later down the road.
The end result can be seen in the photo, conveniently packaged in 700mL containers, and since they're going back in the freezer, I've defeated the purpose of making room. But at least they're more attractive in this form. With 2½ containers filled, that yields 1.75L of duck stock. Early in the process, the duck aroma was pretty strong, but towards the end and it had turned into a more neutral poultry stock, albeit much stronger and deeper in flavor than chicken or turkey stock.
The next step is to take all of the uncooked skin scraps that I've got and render out the delicious duck fat. But not today.
I don't have any immediate plans for the stock, but I'm sure I'll make a risotto or sauce or something in the next couple of months. Perhaps I'll take a cue from the Marx Brothers.