I would have to thank Robin Robertson and her superb cookbook, Vegan on the Cheap (VOTC), for the idea of saving my veggie scraps to make vegetable stock. Seriously, genius idea.
I made my second batch ever (I had to try it out before posting anything on here. I'm a perfectionist who can't take constructive criticism. I'll admit it). I first made it several weeks ago. Saving vegetable scraps (ends, peels, inedible bits) has been pretty easy, so I've found. I have a large tupperware stowed away in my tiny freezer, and I just pop bits of carrot/onion/celery/cabbage/etc in there when my fiance and I prep them for meals. It takes us about a week to two weeks to get a sufficient amount for stock (I know it's time once I have to man-handle the tupperware lid to get it closed!).
Just throw the veggies in a large pot, fill with enough water to cover the veggies, add spices (salt/garlic/peppercorns), heat to boiling, then cover and reduce to simmer. Then, all you do it strain the liquids and store in containers of about 2 cups each. I usually freeze 3/4 of what I make. Phil's always complaining about how stuffed our freezer is, but it's FREE STOCK. The boxed and canned junk is super expensive, anyway.
After I simmer the veggies for about an hour and put them in a strainer, I smush the crap out of them to get all the liquids I can!
YAY FOR FREE STUFF!!