A few tips for odds and ends that add flavor without lots of $ and/or have a good shelf life.

When making beans (pink are my favorite, Dominican style), throw a hunk of calabaza into the pot, adds sweetness and thickens the "gravy" a bit.

Soups, throw in a hunk of parmesan rind. Adds texture and flavor while using something that would otherwise go to waste.

Buttermilk! For sauces on pasta (really, it's great for the base of a roux/sage sauce), pancakes, baking, lasts much longer in the fridge than regular milk, and adds depth without being as high in fat as whole milk or half and half.