Every week I receive sale flyers from all our local grocery stores in the mail. I used to run to each store and purchase the items I needed that they had on sale. I got smart and started shopping at our local Walmart Supercenter which honors all other store sales ads. I just present my sale flyers at the check out. While at the grocery store, ideas cross our minds about how the store could improve their services, additional products that could be added, etc.
Many food cooperatives offer discounts for members who volunteer.
I'm an at-home mom who works six to eight hours a month at home at my convenience. When this is combined with bulk buying and sale items, this can add up to big savings. I write action letters and proofread but member work can be tailored to your talents. I buy a few boxes when it's on sale, plus a large canister of plain, store-brand oatmeal. Add 2-3 packets of the flavored kind to the plain canister.