Compost leftover food and organic material to help keep down waste even further. Some cities collect compost, but otherwise you'll need to compost it yourself in your back yard.
Items you can compost include leftover food, extra pieces of ingredients (like the leaves from carrots), and unbleached paper.
Compost by collecting all of these items together in a large box outside. Turn the mixture every few weeks and add soil, until the whole thing looks like a single mixture. This can often take months.
When the compost is done, it can be sold or it can be used to provide nutrients to your own yard or garden.
Little extra effort but it proves its worth in a big way.