About using fans - It usually cools off at night - so use that to your advantage and have fans running at night to bring in the cooler air. Then you can use your air conditioning only during the day.
Be aware of the patterns of cross-ventilation of your home or apartment. My apartment, for example, has an updraft in the front hall, so the cool air circulates better if I keep the front door open. I have put a lacey curtain on the open door for privacy, and to reduce bugs, etc. Also, I have fans in almost every window to help circulate the air through the apartment. By doing this nights, it avoids the build up in heat I would get without the circulation of air.
Of course, it helps that where I am the air is cool at night - but try to become sensitive to how you can use similar strategies and you will save on air conditioning bills. (I did this in church at my choir rehearsal tonight, placing fans in just the right places, and managed to cool down the place much more efficiently and quickly than usual.)
