When looking for a housecleaning service, find one that uses earth-friendly, biodedgradable products. Or, alternatively, you can supply your own products.
For most recipes, preheating the oven isn't actually necessary and uses up more electricity or gas. Turn the oven on when you are ready to put your food in, and you can conserve more electricity gas.
Use biodegradable sponges. You might not think of sponges as having an impact, but think of how many we use in a lifetime. Every place you can make a change will have an impact.
There are a number of sites that will help you remove your name from direct mail (i.e. junk mail) mailing lists. Register with them and save energy and resources being wasted on delivering to your mail box a bunch of crap you have no interest in.
Look for biodegradable doggie poop bags for cleaning up after your pooch. There's a lot to clean up after over the life time of your dog. Help it all return to earth faster by avoiding non-biodegradable plastic baggies.
Check out the products at Preserve Products and pick up some toothbrushes made from recycled plastic. And then, when you're done using them, you can send them back to Preserve Products, in the packaging they provided when they shipped them to you, and they will recycle your toothbrushes, to give them yet another life!
When you go to a fast food restaurant, think twice about the trash you throw away. A lot of the containers you get your food in can be recycled. Ask for a bag, and bring home any recyclables to throw in your recycling bin at home.
Check with your local grocery store to see if they recycle plastic bags. Most do these days, and even if you use re-usable shopping bags for your grocery shopping, you can bring in other types of plastic bags like ziplock bags or other bags used for food packaging to be recycled instead of just adding more plastic to the landfills.
When you are washing your hands, don't leave the water running. Since you should be scrubbing your hands long enough to be able to sing the ABC song, that's a long time to leave the water running, especially if you aren't actively using it. Turn it off after you wet your hands, and back on when you're ready to rinse. You'll save a lot of water.
Keep recycling containers or bags in different parts of the house. That way when you have a used-up toilet paper tube or empty shampoo bottle you will be more likely to recycle it than just throw it away.