Not the Wall Street kind, but we're sort of talking about money. Done correctly, stock is free. Or at least, the cost is buried in your water and energy bills. It's kind of like compost - turning garbage into something yummy. Just a little more direct. I don't have a recipe to share, and a picture isn't very exciting, but this is how I make my stock.
1) Save anything yummy. Never throw away a bone, or any remnants of the holy trinity (onions, celery, carrots).
2) Freeze it. I keep a bag of miscellaneous bones in the freezer, and a separate bag of carrot and onion skins and ends, and celery tops, bottoms and hearts. Leeks often end up in there as well. This lets me use the scraps from several meals to make a stock, instead of throwing away rib bones here and there and waiting until we cook a whole chicken.
3) Consider how much of a purist you want to be. I toss all bones in together, and I don't pay attention to ratios of vegetables. Sometimes something that has been smoked ends up in there. If you want to make real separate chicken, beef, and vegetable stocks, you'll need to keep more bags in the freezer and obviously it will take longer to save up enough for a batch.
4) I'm going to skip ahead here a minute and chat about straining. In a word, it's a bitch. I've tried several methods and they all suck, mostly because it's really hard to pour a giant pot of liquid and gunk through anything. I've finally solved this problem, and I have to give credit to Not Michael Landon, as well as Reynolds. I'm not a product pimp, I'm not getting paid or freebies, and I'd gladly use something generic if I'd found it, but this little baby made my life a billionty times easier:
http://www.reynoldsstuffingsacks.com/. So, instead of dumping your odds and ends in a pot, dump them in a stuffing sack, tie off, then shove them in a stock pot and cover with water. Or even better, store them in the stuffing sack in the freezer in the first place (inside another plastic bag, I wouldn't worry terribly about freezer burn, but let's not invite it).
5) Bring to a boil and simmer. How long? Eh, 'til it tastes good and you've got some time to put it away. I usually have it going at least overnight, usually until I get home the next day. Just on the lowest setting where you get a bubble or two now and then, enough to keep it from growing bacteria, but not send your energy bill through the roof. I have a flat-top electric stove, so I don't consider the risk of fire to be high, but if you do, or if you have a gas stove, you can always use a crock pot.
6) Taste. Be careful, this sucker's been boiling awhile. I don't add much seasoning or herbs to my stock because I like to leave it a blank canvas for when I'm actually cooking with it, but I will add a bit of salt just so the flavors come through enough to tell me it's done. It's done when it tastes like stock, not water.
7) Cool. This is tricky. We're about to put boiling liquid in the freezer, so it needs to cool down. Start by tossing the stuffing sacks; those bones are just holding heat. It's tough to cool down a large, hot stockpot, but that's also an easy container to ice down. My stockpot fits pretty well on ice in my dutch oven, but if you can poor it into smaller containers first that you can put on ice, that will work faster.
8) Pour into a muffin tin. This will give you nice little chunks that are a good volume for recipes, and also melt in a reasonable amount of time.
9) Be sure the tin has cooled to room temperature, then put it in the freezer. If you want a lean stock, cool it further in the refrigerator first, then skim the solidified fat off the tops.
10) Once frozen solid, pop the blocks out of the muffin tin, and store in a large plastic bag. This isn't super easy. A butter knife and a strong husband helps. My muffin tin is looking pretty beat up from the experience too; I'm thinking about picking up a cheapy just for this use. I'm not thinking Reynolds can save me here.
That's it. Takes a lot of time, but it's all passive, and it's really not rocket science. I think I burnt it once, but all things considered it's forgiving. Then use your little hockey pucks to your heart's content in soups, stews, casseroles, rice, or as extra encouragement for your canine picky-eater. The usual places.