Low-Cost Measures

Install a low-flow showerhead.
Install foam gaskets behind outlet & switch-plate covers.
Put rugs on cold floors
Install and properly use a programmable thermostat
Switch from incandescent and/or halogen bulbs to compact fluorescent light bulbs (CFLs) ...
Buy surge protector strips for your appliances, so you can turn off several at once, while protecting them from surges.
Install a low-flow showerhead and save up to 15% of your home’s water use
Air seal your home against energy draining drafts.
Fix any leaks in your pipes and faucets
Swap your incandescent holiday lights for LED holiday lights.
Replace incandescent nightlights with LED or luminescent models
Use ceiling fans to save energy year round
Install automatic lighting controls in your home
Make sure your heating system is properly maintained
Insulate your hot water pipes to minimize heat loss
Improve the efficiency of your swimming pool/spa/hot tub
Consider swapping your desktop computer for a laptop model. Laptops can use 90% less energy than a desktop

Source Material: Washington State University Cooperative Extension Energy Program at the NW Energy Efficiency Alliance. January 2003