First let me state the obvious; the most efficient way to keep your air conditioning from jacking up your electric bill is to simply not use it. Try your best to not start running the A/C because once you get accustomed to that nice cool air it is very hard to go without it. Remember that everyday you avoid turning it on is a day of cost savings. Try following these steps and save some money:
Open the windows in the evening. During the day you want to keep the outside heat from entering the house, so you want to keep the windows closed. But in the evening the outside temperature will fall lower than the inside house temperature, so you want to open the windows to let the hot air out and bring the cool air inside. You can make this method even more efficient by turning on your ceiling fans or placing a box fan in a window. Not only will this lower the inside house temperature by a few degrees, the added efficiency of the fans will create air movement and make you feel cooler as the air moves across your skin.
If your home has a house fan in the attic you can turn that on and open a few windows and you will get outstanding air exchange throughout the entire house. Running that big fan is much more cost efficient that running a central air conditioner.
If you must run the air conditioner, then get a programmable thermostat. Programmable thermostats are designed to adjust the temperature according to a series of programmed settings that take effect at different times of the day. You can realize tremendous savings by letting the inside temperature rise when you are not at home and then cool right before you get home. For example, if you leave for work everyday at 7am and get home around 6pm then you program the thermostat to let the temperature rise to 85 degrees at 7am and cool to 78 degrees at 5:45pm. Doing this means your A/C was not running all day to cool a house that no one was in and you didn’t feel an instant of discomfort. You can program a different schedule for weekends when you are home more often. These thermostats are inexpensive, $30 to $50, and will pay for themselves in no time.
Go old school! Hey, I know it’s hard to believe but humans actually have survived without air conditioning. Put on your shorts and flip flops, grab a cold drink and go sit on the stoop or go visit someone with A/C! Their are lots of public places with A/C like the library, mall, movies and restaurants. Be creative and you will find that your frugality will reward you!