Install two-layered opaque curtains and drapes over your windows. Make sure they're tight against the window to help prevent the sun's heat from entering your home. Choose light-colored fabrics to most effectively reflect the sun's heat. The tighter the curtain is to the wall, the better it will reduce heat gain.
Apply weatherstripping and caulking to seal any cracks around doors and windows, which will stop warmer outside air from entering your home. Replace any old or leaky windows.
Create shade by planting trees, shrubs and vines between your house and direct sunlight. Shading your house can reduce the indoor temperature by as much as 20 degrees Fahrenheit. Plant trees and foliage on the west and south sides of your home for the most effective shading.
Install exterior shade screens over windows exposed to direct sunlight to block the heat from entering your home. You can also use bamboo blinds.
Install cost-saving ceiling fans in your house; these use less than 1/10th the electrical wattage of air conditioners. Make sure the ceiling fan is set for "summer" so the air is blown downward.
Set your air conditioning thermostat 15 percent higher for eight hours each day, or install a programmable thermostat that will do it automatically. You can save as much as 10 percent a year on your electricity bills by raising the thermostat.