Without a plan, you often waste food or breakdown and have pizza delivered. According to several surveys, most families have 10 go-to meals. Write a plan out at the beginning of the week (or better still month) and add the necessary ingredients to your shopping list. One day a week have a leftover day (my friend calls it LOF - leftover Friday). Keep a folder with favorite recipes and stock up on necessary items to make several meals that don't require an additional shopping trip.
Note: Keep your plan/calendar and use it again several times during the year.