What are some good ways to stretch the life of perishable foods?

Wilted fresh produce can be either cut and put in ice water--like celery or carrot sticks--or used in soups.

A big thing is to use winter storage vegetables and fruits. Favorites of ours in that category are acorn squash, pumpkin, carrots, potatoes, apples, onions, garlic, butternut squash, and turnips. These will keep for a very long time in a cool room. I still have a pumpkin left over from October, and just used an acorn squash from December.

If your cabbage is about to go on you, make a small batch of slaw. You can make something Southern (but adaptable to the north) called chow-chow; good on hot dogs, like saurkraut, but made like a pickle relish in a jar.

I created a root cabinet from the well of an emergency ecsape window in my basement.  The only materials needed were a few sheets of 2 inch foam board, some quarter inch hardware cloth to keep the mice out, a few feet of angle iron to support the foam where it meets the window and some spray foam insulation.  It's bigger than a large fridge and the potatoes, beets, carrots and onions are keeping very well in it. The window serves as the fridge door.  Total cost was under $100.

Many root,tuber,and other subterranean edibles hold up well in freezing temps with a little straw spread on the ground above them.
if you cut a head of lettuce in half and use the core first,it will last much longer.

If i have herbs about to freeze,i uproot them,put them in a vase with water and give them a sunny window
Meats including fish,dont spoil as fast if they are kept dry.
If i get meat from a supermarket,the first thing to go is the plastic and usually soggy diaper.i then set a bowl upside down on a plate,put the meat on the bowl,use a larger upside downbowl to act as a lid over the smaller bowl and meat.just drain or change the plate daily and ive had even fish last a week or more.

I tend to eat perishable foods as they ripen in season from the garden.  In hot weather I have to pick stuff quickly before it bolts or tastes bad like lettuce or carrots, but in the cool fall I preserve things by harvesting only as needed up until the threat of frost.

During the cold months, I mostly eat vegetables that can store for months in the refrigerator or my root cellar (at about 34F right now) and forgo out of season veggies that cannot be preserved.  I've got carrots from my garden last summer that are still good in the frig, in plastic bags, which is much better than store bought carrots that never seem to last more than a week or two.  Beets last for months refrigerated also.    Winter squash stores best in the bedroom where its about 50-55F.  Potatoes in the dark root cellar with the temp just above freezing store for months, sprouting only when warm temps come in spring.  Onions are in a cool dry spot of my basement