Not much. This last year (covid) has really made me think about how we can save food and money.
Bread can be frozen.
Peppers you can chop up and freeze.
Bananas we freeze when they start going bad and use in smoothies or banana bread.
Buying frozen veg (broccoli, cauliflower, carrots, peas) and fruits (berries) instead of fresh.
Freezing meats - we freeze chicken, beef, pork etc.
Freezing fish.
If I notice things are going bad then I will think of a way to use them up. Stuff like spinach can be thrown into a smoothie. Potatoes can be made into fries, mash, roasted, soups, hash for breakfast, etc.
If we have parsnips we will throw them into a soup if we haven't used them all.
Meal planning is the biggest thing though. You are less likely to waste food if you plan in advance. We cook maybe three times a week and none of the meal goes to waste. Leftovers can be frozen or eat at lunch time, especially now we are at home.
Things like tomato paste and canned tomatoes can also be frozen if any are leftover.

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If I have yogurt that is going to go bad but I won't eat in time then I will bake some muffins or sweet loaves which require it.
There is always a way to use things, sometimes you just need to think outside of the box.