Some easy ways to reduce your monthly utility costs are:
Turn off lights when not at home or when you are not using them. Don't run your stove or oven longer than needed. In the colder months: Set the thermostat between at 68 degrees or, if comfortable, set it a bit lower. If you notice a small draft under your front door, roll up a towel and put it along the bottom of the door to reduce heat and cooling loss. Small gaps around and in window air-conditioners may allow warm air to leak outside. Please be cognizant of this. If you have a (or even 2) window air-conditioner (even one the plastic vents installed for a portable air conditioner) in your window, there is a chance that you could experience higher than normal heating bills due to draft/heat loss. Be sure to check your windows to make sure they are fully closed.  The best way to do this is to close the upper and lower sash and to lock them together.
For more information, go to the Energy Conservation Tips post.