I don’t think anything I do is unique but other than growing your food go to a u-pick farm and pick by the bushel and can vegetables and fruits. Learn to bake, make jellies, jams, pickles, sauerkraut, pasta, noodles, dehydrate fruits, vegetables and herbs, make jerky, smoke fish, make laundry soap- the list is endless. Also buy meat from a farmer or hunt and fish.
Read the weekly ads, think outside the box, don’t go to the store hungry, Use coupons when you can. In my area they are pretty scarce for anything I would buy. Shop more in the outer areas of the store first. They usually put the processed foods in the middle and check the upper and lower shelves as they put what they want you to buy at eye level. Check the discontinued area for bargains. I found led bulbs that way very cheap.
Do you live in an area where you can pick wild foods- berries, apples or grapes for instance? Do you have neighbors that have fruit tress and don’t use all the fruit or nuts? Do you or a neighbor have a cow or chickens? Some places people cannot sell raw milk except for animals but I would drink it if I knew the person. Is there a thrift bakery nearby? There used to be one near here and you could get a bagful of bread and pastries and some was good for people but sold for animals or chickens.
Just a few ideas off the top of my head and you probably already heard them or do them. I would like to hear what others have to say.