I'm cooking for two but I really don't think it's all that different. What works for me:
- There's a piece of paper on the refrigerator. When I run out of something we use "all the time" (eggs, olive oil, salt, peanut butter, chips), it goes on the list.
- Before I go to the grocery store I review recipes and decide on two or three dishes I'll make that week. Doesn't have to be fancy; it could be "roast chicken with frozen string beans". Or chili. Or pork chops and sauerkraut. Maybe we have dinner guests that week. Whatever, all the ingredients go on that piece of paper.
- Just before I leave the house to go shopping, I check the pantry, fridge, and freezers (free-standing one downstairs) to make sure I have enough of things. Need an egg for a recipe? Count it, knowing that I'll be making one or two eggs for breakfast every morning. Teaspoon of rosemary? I make sure I have rosemary and cross it off the list.
- At the store, I try to buy just what I need. If the recipe calls for 12 ounces of chicken breast, I riffle through the gondola to find a 12-ounce package. Or I'll buy one-pound package and know that I'll have four ounces left to top my lunch salad one day that week and adjust those purchases accordingly. Sometimes that's hard to do -- the ribs come in a three-pound package and I need only two pounds. Then I'll stuff the rest into the freezer. I know it's sometimes more expensive to buy just the amount I need. But it's not inexpensive to throw away food that has gone bad or gets lost in the freezers.
- I have certain "use-'em-up" meals. Lots of odd veggies can go on salads. Or in frittatas. Or in soup. So if I know I've got a fair amount of odds and ends hanging around, I use 'em up by making one of those meals for the weekend or following week.
- Old crackers can become bread crumbs. If I buy a loaf of bread for DW, I'll freeze half of it right away so it doesn't go bad if it's not a bread-eating week. I quit buying fruit because I don't need it; I'll buy it if DW asks, but only in bulk; no bags even if they're the Deal of the Century that week. We rarely go to Costco because, despite the prices, it's just too much to use up on a timely basis.
Sometimes, though, things sometimes still pile up. I stocked up big-time on frozen vegetables when they were on sale this fall but didn't cook that many meat-and-veggie meals so I've got a lot to use up. I'll have to plan for more meat entrees (steak, chicken parts, fish) knowing I've got the veggies and starches covered. It's inventory control, and generally it works pretty well without boring us silly.