This may seem like a "duh" thing, but after years of throwing away unusable vegetable scraps, I have finally seen the (green) light! Here's what you need to start doing TODAY:
Get a gallon-size zipper bag and keep it in your vegetable drawer. Just keep it there. Every time you slice some celery, peel a carrot, chop the stalk off your broccoli crowns, loose the green leaves of your leeks, have a sad little Charlie-Brown like stalk left from harvesting your herb leaves ... (make sure it's washed and) toss it in that bag! Once you reach a critical mass, which for us does not take very long at all, you've got the makings of an exquisite broth! You can fill up a pot with just water and vegetables, or the next time you have meat bones of any kind, throw them in a pot with your scraps, simmer for an hour or so, and you've got broth!
"Why do I want broth?" you may be asking yourself. Because it tastes better than water, idiot. Boil your rice in it, wilt your greens with it, make sauce out of pan-drippings, use it as a soup base, anything you can think of. I keep an old sport water bottle in my fridge door full of broth so I have it on hand whenever I want to pop the top and squeeze a little broth into the party.
One thing to note: vegetable broth will last longer in the fridge than meat-based broths will. So if you have an immediate plan for your broth, great! If not, invest in some freezer bags, measure out 1- or 2-cups at a time, and freeze them until you need them. Never buy a can or box-o-broth again!