One of the ways I feed our family of four (hubby and I, and our two boys - aged 5 and 2) on $25 a week is by meal planning. Every Sunday when we sit down to eat lunch together, I make sure to have a pen and paper handy. I take suggestions as to what the boys want for dinners for the week.
Meal Planning is fairly simple, just takes a few minutes to get done. And it saves me a lot of money each week!