There's nothing like homemade stock. There are good commercial stocks out there, and I use them, but they never are as rich and flavorful as the stock I make myself.
I have spoken before about thrift in cooking. I save old bread, and find recipes for radish and carrot greens I would otherwise throw away. For my stock, I save the vegetable trimmings, rib bones, poultry carcasses, and ham bones.