It feels like I need to write this grand amazing start to my post on vegetable stock, but I am coming up at a great loss. Making one's own vegetable stock... it will change your life. Not true, but it will reduce your trash output, save you money, give you nutrients, and make your other food taste better. The only thing it won't do is your laundry or go to work for you.
The start to a great vegetable stock is great scraps. The only vegetables I don't recommend using are starches like potatoes or rutabaga; acidic foods like tomatoes, or ones that stain things pink such as beets. Maybe not asparagus either, it might make the stock smell strong. The most often used vegetables in my stock are: onion peels and tops, bell pepper ribs, carrot ends and peelings, celery bits, corn cobs (uncooked), eggplant, squash, zucchini bits, garlic skins and errant pieces, and stems from any savory fresh herbs.
My collection method is to keep a gallon sized freezer bag in the freezer and fill it as I go. If I have a large amount of scraps from say, vegetable soup or fried rice night, I'll pull the whole bag out and dump in the scraps. Other times I use the Rachel Ray method and employ a scrap bowl dedicated to vegetable peelings and hunks. Then those get put in the bag. Once your bag is full, it's time for a fun filled Sunday afternoon of stocking.
Dump those cold veggies into a large stock pot (really, large) and cover with water. Don't fill it up too much. You don't want it to boil over. Then toss in some herbs.
The result: herbaceous vegetable juice.
Side effect: Anyone you live with will think you made delicious, ready to eat vegetable soup. Which now that you have the base for it, you can.