I went through this for years and was always felt so discouraged and guilty. I didn't have the repertoire or financial pressure to use the "leftovers". It changed completely for me when I decided to stop buying cuts like packaged chicken breasts and started buying whole chickens and making stocks and sauces. Now when I look in the fridge at the end of the week and see old, sad vegetables I get excited because I'm going to turn them into delicious stock. I feel so much better because my food waste has reduced by an order of magnitude, the food is tastier, the house smells great, and cooking this way is compatible with local, sustainable agriculture (I'm looking for a poultry operation in my area). But I have to acknowledge, it's a lot easier because I work from home.