1. Keep your air conditioner thermostat as high as you can with comfort.

2. Use a fan when you can; they eat far less energy that air conditioners. 

3. Whenever it's cool and fresh outside, say, after a thundershower, crack your windows an inch or two to create a draft that'll refresh indoor air. 

4. Apply low-cost, low-E films to window glass, which can save you up to 15% on electricity bills.

5. Close blinds and curtains in peak sunlight hours.

via plentymag