12 Tricks to Make Groceries Last Longer and Save Cash... Saving on groceries doesn't just stop at the supermarket checkout. Have your dollar go even further by preserving your food and using some tricks to extend the life of your groceries. If you're throwing away food, you're wasting cash, and all the tips you've used to save money at the grocery store will be for naught. By learning how to preserve food, you're helping your wallet and the environment by reducing waste.