Carpool to stores, shop around for best prices, then cook/prepare your lunches/meals for the next week.
I often ride with others when they make a grocery run, giving me a chance to compare prices & save on gas. I only get 1 - 2 things due to lower prices. Later I go to my regular store.
At home, I start making lunches/dinners. I reuse frozen food trays and make my own microwave dinners. Example, 1 pan of lasagna makes 12 servings, I make12 pancakes eat 2 & freeze the rest - breakfast for another day. Since I don't cook often, this saves me a bundle. Plus I control the ingredients!