You can stay cool and not run up a huge electric bill with a few easy, thoughtful changes:
1. Set your thermostat as high as comfortably possible – try 70° instead of 68°. Maybe even 72°
2. Keep in mind the difference between the temperature inside and outside (the harder the system has to work to close the gap, the more it will run)
3. Turn your AC up a few degrees when you are not home
4. Invest in a programmable thermostat that automatically regulates temperature
If your air conditioning system is an older system, the best way to gain efficiency is to install a new one. You might be pleasantly surprised at the savings, and the payback period.