We are vegetarian, gluten free, and don't eat processed foods, so I can never find coupons for what I am willing to feed my family.
The gluten free flours thing especially sucks...I envy those who can buy whole wheat bread flour for cents per pound. So, we are part of a food buying group (like a coop without the store front), which cuts out the natural foods store middle man. It saves us a ton, and we can still get organic, whole foods. (They don't have produce or milk, though, so I grow what I can and we have to buy the rest). I make yogurt from milk (a gallon of organic milk may be expensive, but it's way less than buying 4 quarts of organic yogurt!)
It would be nice to get premade food sometimes (e.g., an Amy's gf pizza) but it's so expensive, that I don't know if a 50 cents off coupon would really make enough of a difference.