I usually buy in quanity and repackage and vacuum seal. During the growing months I have a garden, except for lettuce. Soil wasn't sweet enough and it was bitter. I also, plant herbs and dry them, parsley, thyme, basil, etc. We have blueberry bushes that produce mega quanities (Lord, I've given away gallon bags of them) and blackberries here.
I don't use coupons as much as I use to. I found that I'd purchase different things that I normally wouldn't with them. Coupons now only for the absolute everyday items now. Shop sales, freezer is to the point that I don't need to get meat unless I find a good deal or need something specific. Basically, I just shop the sales!!! Then stock up. We have 3 grocery stores right next to each other, so make my list and I'll hit all three, if need be.
I also don't buy a lot of pre-packaged food. Homemade here. Cost much less!!! I have even made my own Rice-A-Roni. The real only take out really is Chinese every once in a while or a pizza, but I usually even make my own pizza with my bread maker. Usually use my carcasses for soup, pot pies, homemade stock. I don't buy anything at full price!!! I'll wait for a sale.
Even if we consider this being frugal. Its just plain better for you and taste better!!