You've probably already thought of most of these, but here goes:
1) switch out the lightbulbs in your house to 'green' fluorescent ones that use less energy.
2)Keep on the kids to turn out the lights when no one is using the room! ( my dad used to do this one in the 70s- he didn't know how progressive he was!)
3)We use cold-packs and insulated lunchboxes with a lot of small bento or mini tupperware containers for school and work lunches. My son takes a cloth napkin and I got a set of cheap silverware from IKEA that we use for lunches, so if we lose one, it isn't like it was the good silverware. His school now has a 'waste-free' lunch initiative going on, and he has gotten to show his waste-free lunch box almost every week. He loves having all the little boxes and containers to open.
4) Recycle, recycle, recycle! This one can be hard if your neighborhood doesn't pick up your recycling, but I think most places do now. Once you get in the habit of doing it, it is really second nature. We keep a recycling bin in the kitchen beside the garbage and sort as we throw.
5) Do you have a yard? Make a compost pile on the side or back of your yard! It is easy and non-smelly ( I was worried about smell before we did this, but it has never been an issue). We got some metal poles and green plastic mesh at Home Depot and just made an open square on the side of the house. You can also just buy a compost bin or roller- it will make everything break down much faster and is very contained.
We dump in: Raked leaves, grass clippings, pine needles, veggie waste,coffee grounds, eggshells and fruit peels. I collect all the kitchen stuff in a tupperware container by the sink for a few days, then my son empties it out onto the compost pile.
Very soon for fall, we will be clearing out our yard and garden and will add in: nasturtium vines, any annual plants that won't grow back, tomato stalks, bean vines. I sprinkle some bone meal ( get at any garden center ) once in a while and we poke it around every few weeks. It takes a while, but everything will just sort of break down into a rich dark dirt- compost! Perfect for a garden or flower bed.
It is really very little work, and it's really rewarding. My son came running in the other day, yelling " Mom, mom, its actually compost now! It's like dirt!" lol, I had no idea he would get so excited, but he did!
6) Starting a veggie garden, even just our small one, has been really great too. We save money, give away fresh tomatoes and green beans to neighbors and friends and it is great exercise. My son loves to help plant the seeds and harvest things. His friends and our neighbor's little girl come over just to pick beans and tomatoes.
7)We are able to do this because my fiancee and I both work in the same area, so it might not work for everyone. But we carpool 2 or 3 days minimum every week to work. I am really amazed at how much money we have saved on gas!!! Of course, it requires some planning and there are still times when it just doesn't work out- but we do it whenever we can. In addition to being more green and saving us money- I really love being able to drive in with him and talk or just have a little extra time in the morning together.
8)I've switched us over to all 'green' cleaners from Method, 7 Generations, etc. Our septic water drains into Salt Creek, so I am trying to be very aware of what I put into our waste water! There is a 'gree' alternative to almost every commercial product and I have to say that they work just as well. Baking soda and vinegar work really well to clean lots of things. Occasionally I have to use a chemical product for something particular, but we have really weaned ourselves off of them.
These were the main things I could think of- I hope this helps you!!