Reduce, reuse, recycle
I use non-toxic and organic cleaners (and I don't mean Green Works which is not chemically safe at all, it just reuses the bottle)
I buy organic produce, but I get the paper or plastic bag so I can reuse it on cage-cleaning day.

I do not however use energy effecient light bulbs, I have very sensitive eyes and I can't see at all under them. The light output for the amount of watts is actually less if you read the entire box.