Source: graphic-exchange.com via Brenda on Pinterest

1. Figure out what you already have - Assess what's already in your fridge and pantry that will still be good to use for the oncoming week. Make a little mental inventory or write it down on paper if that helps you. 
2. Throw out what went bad & get rid of junk food - It's important to rid your fridge & pantry of stuff that has gone rancid or expired. Take the opportunity to clean out your fridge in preparation for the new fresh ingredients. Get rid of all available junk food by either giving it away, or throwing it away if you need to, but just DON'T EAT IT! If you have a family that "needs" their junk food then just put it in one cupboard or place that's away from view or hard to reach. Junk food is okay to have around on occasion, but not something to make a habit of having around all the time.
3. Make a list of meals - If this is your first time really thinking this one out, please keep it simple. Don't get fancy with new recipes you've never made before, or plan for healthy food you don't really like to eat. Just outline a couple of simple healthy breakfast, lunch & dinner options that you know you will enjoy throughout the week. Write down a couple of healthy snacks too. If you must try a new recipe, limit yourself to just one and make enough to have leftovers throughout the week. 
4. Buy only what you need for ONE WEEK - My eyes are always bigger than my stomach, and I always end up buying more than I can manage to eat or afford. Don't let this happen to you. It's disappointing when you have to throw away expensive or healthy food just because you bought too much and it ended up going bad on you. Buy only what you need for one week! 
5. Keep fresh produce visible - Place fruits, veggies and meat out on the countertops or in the clear drawers in your fridge. Because these things go bad quickly, you want to make sure you're eating them before you reach for something else that could wait. Example: eat your deli turkey slices before your canned tuna; or use your fresh strawberries in smoothies before drinking canned shakes.
6. Shop once a week, cook once a week - I take care of all my grocery shopping usually on Saturdays and I take time to prepare meals on Sunday. For example you can buy ingredients for a fresh chicken salad on Saturday, prepare a large batch on Sunday and divvy it out into 5-6 portions & place in tupperware. This makes packing your lunches easy, healthy, and cheaper than grabbing fast-food during the week.