Dress warm to use less heat.
Dress cool to use less air conditioning.
Close doors and windows tight, so heat or ac does not seep out.
Do not leave the refrigerator door open; decide what you want to eat before you open it!
Turn of lights and appliances right after you finish with them.
Take shorter showers or take baths instead of showers (you'll use less water)

If you want to keep flies and other flying pest out of your home, hang a clear plastic baggie half full of water in the door way or open window. The plastic bag containing water confuses insects with a 3D image, frightens the fly off and disorients the insect’s vision and keeps them from entering your household, and it’s a good way to reduce the use of pesticides.

Before you pitch it, switch it! A battery too drained to power a flashlight might be perfect to operate your TV remote.

Mix one cup of baking soda, one teaspoon of liquid soap and several drops of an antibacterial essential oil such as tea tree, peppermint, rosemary or eucalyptus. Add just enough water to form a paste, and use it with a sponge to scour bathtub surfaces.