First, be diligent about unplugging any extra camera or cell phone or iPod or other chargers when not in use. Unplug any clocks that you no longer pay attention to, or any VCRs that don’t get steady use. If you don’t need to turn on lights, don’t.
Be sure that windows not often used are closed and latched, especially those subject to extreme heat, cold or winds. Check any attic or roof vents to be sure they are properly set or adjusted.
Next, replace your HVAC system filters regularly, and see that dryer vents, bathroom vents and exhaust fans are clean and free of accumulated dust, dirt or obstructions.
Examine all exterior seams between window and door frames and walls to insure that they are filled and appropriately caulked to be weather-tight. For many homes, especially in windy exposures, most heat enters or leaves by means of such un-caulked seams and cracks.
If at all possible, avoid using a home entrance that is subjected the most severe seasonal weather extreme. If your home has a slab on grade or an uninsulated perimeter foundation wall, consider placing yard mulch and leaves around the perimeter as extra insulation as winter cold approaches.
Consider adding light-colored drapes or sheets inside any glass that receives intense sunlight or heat, to reflect and reduce heat gain. When winter sun is at a low angle, consider draping furniture or even walls that receive direct sunlight with dark-colored fabric, sheets or blankets, to absorb and retain the sun’s heat. Add mats or rugs to any floor surfaces that are seasonally cold.
Use fans to better distribute heated or cooled air and to improve overall comfort.
Consider adding a windbreak of evergreen shrubs or snow fence from 10 feet to 30 feet from your home in the path of the most severe winter winds, to moderate their effect. Use deciduous trees (that shed their leaves in winter) as shading devices in the path of the strongest summer sun.
If you are in an area that uses substantial air conditioning throughout much of the year, consider adding light-colored roofing or roof coating to your home, to increase its reflectance of the hot summer sun, and thereby reduce your cooling load.
If you need to take even stronger action against excess energy costs for your home, ask your local utility company if they provide free energy audits that can suggest improvements. Also ask if they finance energy-saving improvements or offer energy rebates. Lastly, you can seek help from local environmental advocacy groups or any reputable architect or builder.