Many of my recipes call for a tablespoon or less of tomato paste and in the past, had I noticed that in a recipe, I might be inclined to just leave it out since opening a 6 oz can of tomato paste for only one tablespoon seemed a real waste. Paste will mold within about a week's time in the fridge so storing the leftovers and using them before they went bad has always been problematic. Buying the paste already in a tube is a great alternative but the cost is triple that of a can, hardly practical for the amount of cooking in this family.
Solution: Store the paste in a Ziplock bag in the freezer. Depending on how much is left in the can, use a snack or sandwich bag and press the paste to an even layer, forcing out all the air to the edges. Then use a finger to draw through the bag and divide the paste into approximately tablespoon size squares. For reference, a 6 ounce can is approximately 10 tablespoons of tomato paste (it says so on the can.) If 2 are used in the current recipe then the remainder when pressed into an even layer can be divided into 8 equal tablespoon-sized portions. Place in the freezer flat until it is frozen, then when you need paste, simply open the bag to remove an already measured portion.
Tomato paste has a number of flavor enhancing acidic compounds and can be added to almost any savory dish without making it 'tomatoey', but instead adds richness and depth to almost any stock, gravy, or sauce no matter the ethnicity of the cuisine. With this tip you never need to be without a premeasured bit of tomato paste, providing you the opportunity to add it without hesitation to all your favorite recipes.