Cooling Tips
 

Raise the thermostat to about 78 to 80 degrees whenever you go to bed or leave the house. A programmable thermostat will do this for you automatically.
During late afternoon and early evening, turn off unnecessary lights and wait to use heat-producing appliances. It's also a good idea to shade south- and west- facing windows during the hottest part of the day.
Use ceiling fans to help circulate air throughout the house, and make sure your attic is properly ventilated. A ceiling fan should run clockwise during the summer and counter-clockwise during the winter.
Set the fan on your central air conditioner to "on" rather than "auto." This will circulate air continuously, keeping the temperature more even throughout the house and aiding in dehumidification.
Make sure your window air conditioner is the proper size. It's better to get one that's too small than too large - a larger unit will start up and turn off more frequently and won't do as good a job dehumidifying the air.