i try to buy bulk packages, especially staple meats, from costco. also, cleaning materials, foil and plastic wraps, garbage bags, and other food or kitchen type items.
otherwise, i pretty much try to make the next few days' menu based on what's on sale when i go food shopping. when i see things we consume a lot of, such as iced tea go on sale, i stock up.
in either case, i'm always wary of the date of expiration to the point of o.c.d.. i tend to check everything
, even just to get something a few days fresher.
you can't overbuy too much though, because if it ends up going bad before it's used up, then it's worse than just paying full price on a given day.
i've done pretty well lately, snagging lobsters at 7.99/lb and filet mignon at 3.99/lb.
although, it's gotten to the point where we're starting to look at our pets differently...