2.  Use fans wisely. In just one hour, a hard-working bathroom or kitchen fan can expel a houseful of warm air. Turn them off as soon as they've done their job.
 
3.  Keep the fireplace damper closed. Heat rises, and an open damper is like a hole in the roof. Also, limit use of the fireplace, since fires actually suck heat from a room.
 
4.  Close off seldom-used rooms and shut the vents inside. Shut the doors of seldom-used rooms and close their vents. Also, in other rooms, make sure vents are not blocked by rugs and furniture

5.  Turn down the water heater. The water heater is the second-largest energy user in most homes. Hot water heaters have adjustable thermostats. For every 10°F you lower the water temperature, you can save 3-5% of your water heating energy. Lowering the temperature of a water heater to 115-120 degrees reduces power use without a noticeable difference.
 
6.  Insulate water heater and pipes. Covering your water heater with an insulated "jacket" ($17-$20) will keep costs down, especially if your heater is in an unheated place like a garage. A water heater blanket can save 5-10% of the energy it consumes.
   
7.  Use curtains. Opening curtains and shades on south-facing windows during the day allows solar radiation to warm a living space; closing all curtains at night helps retain that heat. A drape can reduce heat lost through a window by one-third. An insulated drape can reduce it by half. Drapes save energy effectively only if they fit tightly against the window and the floor.