We are not overtly green, but we are becoming more so. There is always more stuff in the recycle bin than in the rubbish bin on trash day. We have reusable grocery bags that get used for 95% of our trips to the grocery stores. I also carry super nice fold up bags in my purse (thanks Kur and Mare!) for other purchased items (books, gifts, etc). We have six CFL bulbs in use around the house, though I'm not ready to use them for reading lights in our bedroom. We rewash our ziploc bags and when the current stash we have are finally so well used we have to toss them, we will get more long term/reusable storage containers (more than we have now, I mean) and not buy any more bags.
But the most surprising green thing we've done lately is not to use paper towels. None. Not a one. We ran out about two months ago and never bought new ones. At first we just dealt with the fact that we were too busy to go get any (usually bought in bulk at Costco) and used old rags and dishtowels for clean ups. After a week or two we both realized, without talking to each other, that this was no big deal. When we finally commented on it to each other, we decided that we didn't need to buy them ever again. And we won't.
We went to our tax guy the other day and calculated that I've only driven about 4000 miles in my car last year. Apparently the average is 12,000-15,000 miles per year. Yes, I work at home, so that helps a lot. My car is well maintained and gets okay gas mileage for a 15 year old car with 175,000 miles on it. (Acura!) But soon I will be selling it and will have to share with Kurt. I've already begun walking to the grocery store and have bought a handy cart for when I have LOTS of groceries to buy. I've figured out local bus routes to places near home and will try to share rides as often as possible.
In some ways, green by omission is so much easier and with each new habit we pick up, the next ones will be easier and easier.