I "cleaned house" in my imageshack account a week or so ago. I THOUGHT I kept those; I guess I didn't. C'est la Vie!
Remember, soup/stews always taste better the next day. This is why a couple of the folks the posted in this thread mentioned making a soup a day before it's intended to be eaten.
Yup, I know how to squeeze chicken for every cent's worth of value out of it. I had to learn, what with feeding 5 kids on a tight budget.
I normally don't make stock until I'm almost out of a batch. Of course, when I make 2 GALLONS of concentrated stock at a time, that means the scraps really add up, and quick. I may have 2 or 3 gallon ziplock baggies full of scraps, especially around the holidays. Those turkey carcasses make for great stock, but really take up room. The leg-and-thigh quarters are about the best deal I've found yet on chicken. 10 lbs for $4.79US. Can you beat 47.9 cents / lb for chicken? That, and it's all dark meat, which I absolutely love. Moist and full of flavor.
If you ever attempt to make a shellfish stock, do this: Saute the shells in a bit of butter first, then add the mirepoix. Once that's caramelized a bit, deglaze with a shot of white wine, then with water. Simmer for awhile. I've been making shrimp stock at work, as I need it for several of my sauces, and the fact that we're always peeling shrimp, so we have the shells; might as well use them. I wish my Chef would order in some lobster bodies and shells. I'd be willing to come in on my day off and make a few gallons of lobster stock. MMMMMMM
I use shellfish (usually shrimp, sometimes also with crab shells, and if I have them, fish bones) stock for gumbo, and occasionally when I make a stir-fry that has shrimp in it.
As long as you have some good chicken stock, good beef stock, and some good shrimp stock, frozen in ice cubes, then packed into freezer bags, you can't go wrong making soup. Unless, of course, the cubes get freezer burn. You'll have to play with how much is "enough" of each kind of stock to fit your cooking style and quantity. Since I have a big family, I go through these things relatively fast. At least, during the winter. Summertime I don't make soups or sauces much, so I don't usually use stock, unless I'm making pilaf. I try to run low on stock during the warm months, so they don't get freezer burnt.
Another thing to consider, when making soup, if you add the veggies with the meat all at the beginning, like in your short rib stew, the veggies will basically cook down into mush by the time the meat is tender. Start the meat, and simmer it in stock, then add the veggies in the last hour. You can add them straight to the liquid, if you want, or, skim off some the fat into a saute pan, saute the veggies, then deglaze the saute pan with the broth from the soup. Dump everything back into the soup and simmer until done.
You also stumbled onto something with the short rib stew. By adding the second batch of veggies, with the first batch being pureed, you created a second layer of flavor in the soup. Chef Prudhomme talks about doing this in his first cookbook. He often adds some Cajun Holy Trinity to a dish, cooks it some, then adds more trinity that doesn't get cooked long enough to turn into mush. This way you can feel and taste the veggies, while the others blend into the background.
You also mentioned that your stew "lacked" something in taste. Did you add any red wine to it? Lately, whenever I'm making a sauce at work that's based on beef stock, I always deglaze with a splash of red wine, then the beef stock. I may only use a couple of tablespoons of wine in a sauce that yields a few cup's worth, but that's all that's needed.