3. Internalize those food storage rules. If you really want to learn to store your food properly or better, there are a number of ideas one can commit to memory or write down and tape on the refrigerator. The California Milk Advisory Board says if you have a lot of butter, it can be stored in the freezer for up to six months (versus in the refrigerator for about four months). Freezing milk, in case you're wondering, isn't a good idea; it changes its texture and appearance. You could take an entire course on storing cheese, but if you have semi-hard and hard cheeses like cheddar and Gouda in your refrigerator, they should be wrapped in butcher, craft, or waxed paper or foil.
Speaking of cheese, one of the stranger suggestions comes from the Ozonator blog, which suggests spreading butter on the cut end of your cheese to prevent it from drying up and hardening: "This is especially effective with hard, wax-sealed cheeses, but it'll work with anything from cheddar to chèvre."
And when it comes to herbs and leafy greens, "they will keep much longer in the refrigerator if wrapped in a damp paper towel," says Elliott Prag, a chef instructor at the Natural Gourmet Institute, a New York City-based culinary arts school. But remember, he says, to "check the paper towel daily and replace it if it dries out."
Prag adds that dry grains will remain fresher longer in the refrigerator, especially if they're in a place free of condensation.
4. Embrace leftovers. Susie Wolak, chef mentor at the Escoffier Online International Culinary Academy, headquartered in Hoffman Estates, Ill., says if you know you're likely to have leftovers, "start planning ahead what you'll be able to make. That beef roast from dinner can be slicked for barbecue beef sandwiches the next day. The ham dinner can be diced for ham-salad sandwiches the next day. The mashed potatoes can be made into dumplings by adding egg yolks and flour and rolled into small balls boiled and served with a marinara sauce."
Those who lack cooking skills and are more likely to be using Chef Boyardee may have to be even more creative—or just go with boring leftovers—but her point is well-taken. If you know what you're doing, you can do some pretty interesting things with your food. Wolak also points out that overripe bananas can be used to make banana bread, a stale loaf of bread makes good croutons, and that older baked goods can often be converted into bread puddings.
Prag says a lot of food scraps make good ingredients for vegetable, chicken, and meat stock: "Save clean skins and clean trimmings of squash, corn cobs, greens from the top of leeks, bones from roasted meats, frames from roasted turkeys and chickens, and stems from fresh herbs. All are great stock ingredients."
5. Research before you toss. There's a website for everything, even the question of whether you can hang onto those grapes just a little longer. Stilltasty.com and ShelfLifeAdvice.com are both dedicated to giving people educated guesses on how long it takes before food goes bad.
Of course, taking all these steps isn't easy. That's why so much food goes to waste and why so much of it wouldn't if we either shopped smarter or heeded one after-meal rule, says Bloom, who urges everyone to make the following their mantra: "Love your leftovers."
Corrected 03/07/13: A previous version of this story misstated the name of the Natural Gourmet Institute.