Using all parts of the buffalo
Growing up with my mother's memories of Poland, I learned not to waste. All chicken bones went to stock, etc. I realized the extent to which this had influenced me when, tonight, I kept the olive oil from a (somewhat expensive) can of sardines for pasta sauce.
What do you do with things that might usually be thrown out?
I grew up in a poor Chinese family and like you I throw almost nothing out. I keep the oil from anchovies and Italian tuna to use in sauces or dressings. When I reconstitute dried mushrooms, I keep the liquid (filtered) and tough mushroom stems to add to stock. I keep leek tops and celery leaves for stock, as well as parmesan and pecorino rinds.
We bought a whole pig from a farmer last winter. When we were talking to the butcher about how we wanted it cut, we asked for everything, the fatback, the kidneys, heart, leaf lard, the lot. I think we gained some cred with them, it showed respect for the animal. I've made salt pork, rendered lard for pastry and cooking, and cured hams. I'm still planning liverwurst, just haven't gotten to it yet.
When we visited my mother-in-law they treated us to fresh lobster. I was horrified that they intended to throw out the shells and other inedible bits, but we were going to a concert before going home or I would have taken it with me for seafood stock. And they wonder why our fish chowder tastes so good.