Stock is a freebie. You get it as a by-product when you are making something else. Many people add onion and garlic to their stock, I make mine plain so I can season the final dish however I like.
Always strain the stock, then you can freeze it in 1 cup blocks for use later. You can also freeze small amounts in ice cube trays for use in gravy. Store it in the freezer in a plastic ziptop bag with a label.
Bell Pepper Stock
When you make stuffed bell peppers, you must parboil the peppers for 5 minutes to tenderize them. Do not throw this liquid away. Strain, freeze, and store the stock for use later.
I use bell pepper stock when I make Spanish Rice or sometimes when I make cous cous.
Every time you peel or chop vegetables, put the tips, tops, and peels in the stock bowl. Your vegetable stock will vary in flavor depending on which vegetables you use.
When you remove chicken bones and skins, boil them to make chicken stock. If you roast a whole chicken, boil the carcass for stock. Buying chicken with the bone and skins is not only cheaper, it gives you free chicken stock. You can remove the bones and skin before freezing, or (if you want extra flavor) after cooking.