Check Craigslist's free section. Among the sales and want ads, Craigslist also has a section with people offering items for free. Many times they stick the items by the dumpster and they get thrown out before anyone can make use of them. Not a great way to go green, is it? Whether you rescue one item or do it regularly, you will be helping. Rescue the items for yourself, your friends, those in need, and the Earth.
Repurpose old items. Take your own old items or those you may have found on Craigslist or elsewhere and use them for something new. For instance, if you get a new entertainment center, but your old one can still be used (even if it needs to be pieced back together), you can use it for another reason. Turn it into a decorative shelf where you can store your plants, books, and more. Refinish an old table or just drape a cloth over it and use it for decorative purposes. Saw an old table in half and add legs to each new half to create two desks. There are so many different options.
If you can't use it, be green and donate it. If you really just cannot use the item, consider donating it to the less fortunate. Think of people you know who are in need first. But if none of them can use the items, upcycle by donating to organizations. Many programs give used furniture, clothing, baby items, household items, and more to those in need. Chances are that what you may consider junk could be exactly what someone else needs but is unable to get at the moment.
If you need the extra money, garage sale it. Donating is a good deed. But if you're strapped for cash, hold a garage sale. You'll still be helping someone by offering something at a lower price than the original sticker. Why throw things away when you can fulfill a need, make some money, and prevent waste at the same time?
Don't let good things go to waste. If you're walking around the neighborhood and see perfectly good items being thrown out, rescue them. Even if you can't use the items yourself, save them from unnecessary destruction. Find someone who needs the items or sell them in a yard sale. Even post your own Craigslist ad if you can't figure out what to do with them. At least you will be biding the Earth some time and possibly helping someone in need of the item.