Ever since I changed our incandescent light bulbs for all compact fluorescent lights (CFL) in our first apartment many years ago, I haven't stopped looking for ways to save energy and resources. That one change dropped our electricity bill in half.
I try my best not to use or waste energy if there is an alternative. All of our non essential appliances are on power strips so they can be turned off when not in use. That is a huge electricity drain you may not even think about. Hubby doesn't like this one because he has to wait 5 minutes for his TV channels to upload before he can watch anything. I think the 20 hour energy savings is worth the wait. I also turn off all the clocks on our appliances if I can. Do I really need four displays greeting me with the time when I come into the kitchen?
I also conserve water when possible. There is no reason to wash/pre-wash/rinse anything that's going in the dishwasher. If you feel the necessity of doing something about leftover food and debris, just brush or scrape it off into the garbage.
For other energy savings which help you move and burn some calories, you can use a broom on both bare floors and carpets. In is efficient and gets your blood pumping. You can use that same broom on the ceiling to get at spiders and cobwebs, too. Not only are you keeping active, but you are saving on the vacuum bags that you are not filling up and throwing away.
As for running errands, I try to put several together that are located in the same plaza or intersection. That way I can park and walk to the different stores to get things done. Again you are saving gas and emissions by not driving all over and you are burning calories carrying bags or just walking between the errands.
I am sure there are a few more things I can't think of right now. Do you have some green tips to share?