My first recommendation is going to the library and checking out (or ordering through interlibrary loan) books on the subject of cheap eating. To find them try searching amazon.com for books with searches like "frugal living," cheapskate, saving money, "eating cheaply," miserly, tightwad, thrifting, "simple living," .... Do the same online and you'll find thrifting and frugal living websites.
I just searched google using the phrase (no quotes), frugal living websites and it yeilded 499,000 results (with quotes 56,200).
My cheap bible is The Complete Tightwad Gazette
by Amy Dacyczyn
Not all of the tips are on food budget, but if you save money in other areas it frees up more room for the food budget, so it's a win-win.
Some of the tips may seem weird and gross to you, but you take what will work for you, and you leave the rest - and it will inspire some ideas of your own.
Some of the things we do.
buy chicken at no more than $1 per pound for bone-in chicken, and $2 for boneless. We usually buy thighs because they're usually the cheapest. (wings are the exception, because there's too little meat and too much skin and bone to make them a bargain).
Instead of extra lean ground beef, we buy cheap ground beef and combine it with seasoning vegetables and dry tvp granules to use in recipes calling for ground beef. I freeze it in crumbles so I can use what I want.
If you want the recipe it's on my 3FC blog (cheap recipes are my thing)
We're always on the lookout for cheaper sources (this only works if you have inexpensive, reliable transportation). For example, we discovered that Kwik Trip (a gas station/convenience store) sells fruit and potatoes and onions at 39 cents per pound. For bananas this is always the cheapest, so we rarely buy bananas anywhere else (on occasion I buy miniature bananas at the oriental groceries, as a treat). For apples, pears, and oranges it's usually the best price.
We shop oriental groceries for some things. We can get a fancy mushroom soy sauces in a quart bottle for the price of a small bottle of generic soy sauce in the chain grocery stores. We'd save more if we bought it by the gallon. We buy fish sauce and use it in american dishes place of salt or worcestershire sauce (it brings out the flavor in foods, but doesn't taste of fish unless you use WAY, WAY too much).
The fresh vegetables and the fresh seasonings are often much cheaper and are almost always much fresher than in other grocery stores, especially nappa cabbage, bok toy, bean sprouts, green onion, cilantro, basil, mint, exotic mushrooms, eggplant (I love asian long eggplants, hate european large eggplants), some of the exotic fruits like pomello, tiny bananas, lychees, asian pear.
If you like sardines, I find sardines in all sorts of flavors in oriental grocery stores (my favorite are the ones in curry sauce). They come in 6 ounce cans or larger for 99 cents and I usually get two meals out of them.
We shop a store that is a bit like Big Lots (but privately owned) and they get in a lot of junk food (so you've got to be picky), but they also get in some gourmet stuff. Some stuff they get in a lot, sometimes it's a one time event. We've been able to buy cans of organic chicken stock for the past year (49 cents per can) and I got some sea salt seasoning shakers for 19 cents that I later saw in a grocery store for $7 each. We bought fancy bags of beans for 29 cents per pound bag (I don't remember all the varieties, but I bought one of each, and wish I'd bought everything they had - adzuki beans, pink beans, anasazi beans, chickpeas, kidney beans, lima beans, pinto beans).
We usually start at the Big Lots store, because we never know what we'll find there. With the economy, the gourmet and health food stuff they get has plummetted. When they start getting in more health food and gourmet
stuff then I'll know the economy is really turning around.
We buy cheese from local cheesemakers (this isn't going to be available to everyone), and we buy in bulk and freeze). One of the cheese shops had all their Montery Jack varieties for $2 per pound.
We buy cuts of meat that are "old-fashioned." These unfortunately are getting rarer, and while they once were the cheapest cuts, now they're sometimes sold in grocery stores at much higher prices (like oxtails - wonderful for soup, but if you're paying $2 per pound for them, you're getting ripped off. Try to find smaller butcher shops that are actually butchering animals, not just buying factory meat. Their popular cuts will be much more expensive than the larger grocery stores, but the tougher and bonier cuts, and the organ meats will often be much cheaper.
Check out the meat counters. Most of the meats are more expensive than what's in the open cases, but there are exceptions. One of our stores has sales on marinated boneless breasts for $2 per pound (regularly twice that). They have a gourmet thick-cut bacon (we don't eat bacon as a meat, but use it as a seasoning) for $2.50 to $3.00 on sale (which is about the same price as the cheapest packaged bacon in our area).
We shop at Aldi. It's a great store, but don't go on Saturdays or Wednesdays, if you can help it. Wednesdays are when Social Security checks come out, and Saturday is just a busy day in any grocery store. Check the prices though, because not everything is cheaper (most of their produce, with the exception of potatoes, lettuce, onion, and apples aren't usually a good buy).
We buy seasonings from a baking-supply store (most are in tiny plastic tubs rather than shaker containers). The price is at least 1/3 of grocery store prices. I buy ranch dressing powder there (well I used to, now I buy the ingredients seperately and make my own. It's the recipe you'll find if you google "ranch dressing mix recipe."