1) It is best to turn the temperature up 4-5 degrees warmer than usual when you will NOT be at home for the day (ie: at work). Do not turn the A/C off. It will take longer to cool your home and cost more in the long run.
2) Leave the “fan” setting on your thermostat to ON position, so it runs constantly and circulates the cool air throughout the house.
3) Close all your blinds to keep out heat and sun.
4) If there is a door to your basement, shut it. Cold air drops and you will lose your cooling to the basement.
5) Close any registers that are in the basement, this will force more of the cool air to the upper levels of your home.
Please keep in mind that the best temperature difference to expect is 10 degrees cooler that outside.