One of my favorite frugal things to do is make my own broth. Most stock instructions actually have you buy stuff specifically to make it, which is kind of a waste of money. The other option is to buy canned broth or bullion cubes, which is also a waste of money and not very healthy. I also don't like how those taste--too salty. Instead, I make my own stock for free!
I keep two produce bags in the freezer: one for meat stock and one for vegetable stock. When I cook meat, the bones go in the meat stock bag.
When I cook vegetables, the parings go in the vegetable stock bag. The vegetable stock bag can include any parts of vegetables that are clean, not rotten, and not something that one would normally eat. Cabbage and bell pepper cores go in. So do onion and garlic skins and the ends of celery and carrots. I also toss in apple and pear cores, but not too many as that would make a sweet broth.
When either bag gets full, I dump it in the biggest pot I have, fill the pot most of the way with water, and boil it for a couple hours. Sometimes I boil the contents of both bags into one stock. I usually add a clove or two of garlic and a bay leaf to the stock as well. The broth is plenty flavorful and salty enough not to require any further flavoring. When it's done, I strain it and pour it into containers to freeze.
See more kitchen tips at Tammy's Recipes for Kitchen Tip Tuesday.