Be sure your weather-stripping and caulk around all entrance doors and windows is in good condition.
Attics must be ventilated properly. Determine whether your attic ventilation is adequate. Reduce air conditioning needs by installing an attic fan.
Set the cooling thermostat as high as comfortable. The higher the setting, the more energy you will save. Install an automatic setback or programmable thermostat that starts your air conditioner shortly before you get home.
Draw blinds, shades, or drapes to block the sunlight during the hottest part of the day, especially on the south and west side.
You could save up to 25 percent by upgrading your air conditioner. Make sure your central air conditioning system is the right size for the area you want to cool.
If you have central air conditioning, clean leaves and debris from around the unit. Install your air conditioner in the shade. Clean/replace the filter regularly.
A ceiling fan cools fast and costs less than air conditioning.
Operate your stove, oven, dishwasher and clothes dryer in the morning or evening when it’s cooler outside. Instead of using your oven, consider cooking in a frying pan, grill, crockpot, or toaster oven. I have a small counter top oven that I really like. Because it is smaller, it heats faster and cooks faster. You do have to adjust your recipes baking times. It beats heating the large oven, especially to cook a meal for two.