Here are some things that are green that you might not think about.
1) shopping at yard sales, thrift stores and consignment shops- by purchasing items there instead of the brand new option, you are preventing it from ending up in a landfill and you are avoiding the purchase of a newly manufactured item that would have to be shipped from the factory. Recycling, avoiding landfill, avoiding potentially ozone harming gases for production AND buying local!
2) purchasing antique/estate pieces, especially jewelry!-one of my favorites!! My engagement ring is an estate piece. I insisted on it for a number of reasons, but one of the main ones is that there were no new stones mined in the making of it. That means no further impact on the Earth and I feel (a little bit) better about those who risk their lives in the mines. I love diamonds but the stories from the mines are atrocious. Estate items are often made better, coming from a time when the item was crafted by a skilled tradesman instead of being mass produced. All this goes for furniture as well.
3) purchasing an existing house- this is goes along the same lines as above, but obviously on a much bigger scale. Instead of building new, refurbishing the existing one can have less impact on the environment. Think of all the materials that go into making a new home. Also, think about how well made older homes tend to be. If it is still standing after 100 years, that says something. When refurbishing, think about where you are getting your materials from. If you live in the Pacific Northwest, bringing in cedar from Florida doesn't make as much sense as staying local.
4) donating items to thrift stores, libraries, schools, elder care, etc.- again, you are attempting to prevent the purchase of something new by offering a perfectly useable item that would otherwise be tossed.
a) participating or creating a "swap"- I personally love book and clothing swaps. Books take a lot to make, a lot of paper, ink, etc. and going to the library, while a fantastic option, isn't the only way to keep up with reading. Find friends/co-workers who read as much as you do and you will find yourself with more than enough materials. Swaps aren't limited to clothing and books either. Bulk items can be shared, scrapbook or craft items can be swapped, magazines. It is only limited by you.
5) repurposing your stuff- take a second look at the items you are about to give away. Can it be used to serve another need for your household? I need a way to hold my cookbooks on the top of the fridge. My hubby and I went to the store, looked at the options, but none of them were really what I wanted. Suddenly in a flash of enlightenment, I realized we had two bamboo paper trays that we weren't sure what to do with. Now they are sitting on top of my fridge preventing me from a cookbook concussion. Or the wooden shoe shelf that is now serving as a shelving system for the wireless router, cable box and DVD player.
I hope that this gives you some ideas. Just remember, being green isn't an all or nothing choice, it is just a SOMETHING choice. Make your own impact the best way you can.