If you take the time to plan a weekly outline of your meals and shop for all the ingrediants, it's easy to make more than one meal a night. If I'm cooking ground beef for my meal that night, if I'm having ground beef another night that week, I throw in another pound to cook. After, I divide the meat in half and use some for the nightly meal and the rest goes in the fridge.
Sometimes, I'll make the whole meal and place in the freezer. I always keep the aluminum 9x13 pans on hand so I can make a freezer meal for next week or even next month.
The tip is, cook double whenever you can. If you are making potatoes one night, boil the whole bag and make mashed potatoes out of half. This speeds up future meals and saves time.