Of course my favorite way to be green is buying, dressing and decorating vintage. My most prized possessions (that aren't from my mom) are the ones I hunted down to find; digging through piles of stretched out sweaters and plastic gnawed on sippy-cups. Vintage and re-purposed goods are a fantastic way to be unique and not rely so heavily on newly manufactured products.
However, the coup de grace of any vintage find is if it helps reduce your dependency on other products that are wasteful or expensive. Two fantastic examples that we have in the shop right now are vintage pyrex dishes--using them instead of tupperware, not only cuts down on the amount of plastic floating around the planet, it also makes you seem oh-so-domestic, in a Carol Brady kind of way. My other favorite find that I have promised myself to start incorporating into my daily life is cloth napkins. They make any meal or snack seem a little more special--plus they will save your wallet in the long run. We fly through paper towels like crazy at home; I think this will help at least a little.
So no, I can't afford a hybrid car quite yet and my clothes aren't all made of hemp, but every little bit can help and it actually feels good to be responsible (if you look cute while doing it).