I do clip coupons, and I organize them, and I also match them to sales. I only shop every other week (twice a month) for the large items, and then just quick stops for things like bread and eggs. My biggest way to save money on groceries was to just shop my big times like this. Less temptation to buy extra, and it gives me time to organize the coupons I need to use.
I can usually save about $100 off my bill. But again, it is time consuming.