Once you are done with your laundry detergent, put water in it and swish it around really well, I can get 1-4 more loads out of it. And you are rinsing so it's ready to be recycled too.
Same with shampoo or conditioner
You can put ice cream in a "empty" Nutella jar and get the last bits of goodness :)
Jam jar is empty, put some balsamic vinegar in it swish it around real good and you have yummy flavored balsamic for salad dressings
Crushed up potato chips are great for a crust for your breaded chicken, or use in a taco salad for the crunch, or put in soup like you would crackers.
Not everyone can do this, but we don't throw away any leftovers, our chickens and rabbits and worms are happy to eat every last scrap :)