Planning meals so that you don’t waste is helpful.  Also, look in your fridge/pantry before you shop so you can use what you’ve got to create a meal.

Understanding that good, healthy (esp. organic) food is more expensive than junk food but you get more bang for your buck— it’s more nutritional so you won’t need to eat as much to get what your body needs. 

Also, making things like pastas, stir-frys and soups stretch the more expensive foods out. 

Don’t buy small packages or pre-packaged foods— baby carrots, cut salad greens, etc as they’re more expensive because someone else was paid to do the prep.  If you stop buying processed and prepared foods it will save so much over the long run.

I belong to a CSA so from May to mid-Oct I get a bin full of fresh organic vegetables, herbs and some fruits for $500.  It’s a huge savings. 

Buying frozen organic vegetables and fruits are another way to save.  (I always use frozen fruit in my smoothies)

Good luck!