Woe betide any cook who is caught throwing out any usable scrap, or worse, ingredients spoiled from negligence. Letting food go bad is like throwing money straight into the bin.
Short of implementing the industry standard Hazard Analysis and Critical Control Point plan, you can improve your food cost percentage at home by taking tips from its handling and storage best practice. The acronym Fifo (first in, first out) should remind you to use older ingredients first. When unloading groceries, take the time to rotate the older containers of food to the front of the shelf; when cooking, we tend to grab whichever can/bag/tube is easiest to reach.
Industrial walk-in refrigerators can contain hundreds of ingredients. Each product tends to have its own place. In a domestic fridge, there's no avoiding a bit of stacking, but do assign sealed containers to each type of food - especially raw meats and seafood - exclusively. Colour coding is one way to keep track. Cross contamination changes the flavour and smell of ingredients and speeds up spoilage. Avoid overloading a fridge, as cold air needs to be able to circulate.
Finding the right temperature of refrigeration is essential for keeping perishables fresh. Industry standard rules that anything higher than 4.4 degrees Celsius promotes bacterial growth; but freezing temperatures can cause food spoilage as well. Many people think, 'The colder, the better', but if the fridge thermometer reads 1.7 degrees Celsius or below, the chances are damage is being done inside. Strawberries, herbs, lettuce, milk and eggs are a few foodstuffs that don't freeze well.
Do a quick but thorough inventory of the fridge and cupboards before heading to the market. Doing an inventory at short intervals will help you catch an ageing ingredient in time to 'sell it' to lucky dining companions. Browning or drying fruit can happily translate into: 'Sangria, anyone?'