Do you have central air? If not, you may want to practice “zone heating” – basically heating (in this case cooling) only the rooms you are presently using. Run your room A/C only at night to help you sleep, in the baby’s room of course as much as is needed, and other rooms only when in use. Shut doors that have A/C running in them.
If you are using central air, you might try insulating your windows if you rarely/never open them. You don’t have to insulate every window to make an impact. (you can get a plastic sheeting insulator kit at the hardware store, usually a 4 window-kit costs $12) or hanging your storm windows back up if you have them. That can make a big difference, especially if you windows are a little on the older side, or wood framed (wood framed windows never ever ever close all the way, in my experience).
Other general tips:
*Be fanatical about keeping shades or curtains drawn on the sunny side of your house (sun in = heat in).
*Turn off incandescent lights every time you leave a room (they generate heat, and of course, use electricity themselves). It is a myth that this greatly impacts bulb life.
*Only run the washing machine when it is completely full – it uses the same amount of energy for a full or partial load.
*Set your dishwaser to “energy saver” or “no heat dry.” Use the shortest effective cycle (with most newer machines, “light” is more than sufficent for everyday dishes.)
*Separate out laundry before drying – some items, especially synthetics (polarfleece pullovers, rayon dresses, etc), air dry easily without feeling scratchy. Experiment with the different drying cycles to find the shortest effective cycle (timed vs. automatic).
I am fanatically thirfty about my energy bill! Hope some of these ideas help a little.