Rinse berries in vinegar-water (1 part vinegar, 10 parts water) before putting them in the fridge to kill any mold spores. Raspberries will last up to one week, and strawberries up to two with this trick.
Wrap banana stems in plastic wrap because the stems produce ethylene gas that makes the fruit ripen faster. To keep them fresh even longer, separate the bananas and wrap each stem individually.
Store herbs like you would store flowers — with a tiny twist. Place them in a jar of water and drape a bag over the top to keep in moisture, then store them in the fridge.
Same goes for asparagus.
Keep lettuce in a bag with a paper towel to absorb excess moisture, and store it in an airtight bag in the fridge to keep it from drying out.
Store avocados at room temperature until ripe, then keep them in a plastic bag in the fridge for three to five days. Wrap avocados that've been sliced tightly in plastic wrap to keep them from oxidizing (i.e. turning brown). For guacamole, try sticking plastic wrap to the surface of the guac itself.
Keep tomatoes in a bag or box in a cool place until ripe, then store them on the counter. Overripe tomatoes can be stored in the fridge, but the cold air stops them from ripening and breaks down their cell membranes, giving the fruit that characteristic mealy taste.
Don't chop up fruit, veggies, or meat until you're ready to use, since exposure to the air will make all of the above dry out or go bad faster.
Want to make your onions last? Try storing them in pantyhose in a cool, dry, dark place. The air circulation will keep them from getting moldy, and they should stay fresh for about six months.
Store potatoes with apples to keep them from sprouting. Don't store them with onions, because both release moisture and gases that cause the other to go bad faster.
Wrap cheese in parchment paper or wax paper (not plastic wrap or tin foil), or it will dry out because it's not getting enough oxygen.
Don't store your milk in the fridge door, where temperatures fluctuate and it can spoil faster. Instead, keep it closer toward the center of the refrigerator.
You can store butter in the fridge for up to four months unopened, or up to a year in the freezer.
Store eggs near the back of the fridge where it's cooler. You can also freeze eggs for up to a year if you separate the yolks and whites, and add salt or sugar to the yolks.
Keep meat in the bottom drawer of the fridge where it won't drip on other food, and double-wrap it to prevent cross-contamination. Beef and pork will last 1-2 days in the fridge and 3-4 months in the freezer. Chicken will last up to 9 months frozen.
Keep your fridge clean to prevent mold and other microbes from growing, and don't overstock it — the air needs to circulate to keep things cool.
Store brown sugar with moist items like marshmallows or bread to keep it from drying out into a solid block.
Store red spices (paprika, cayenne, and chili powder) in the fridge to keep them fresher and brighter. Light and heat can make them lose their color and flavor.
Store leftovers in clear containers so you'll remember to eat them before they go bad.
Finally, take expiration dates with a grain of salt. That's just when manufactures consider food freshest, but it's often good for longer. To find out how long it will really last, you can consult sources like Stilltasty.com.