Switch to warm or cold water settings on your washing machine, rather than hot. This simple change will greatly reduce your costs with every load. Check the labels -- delicates, colors and many other types of clothes and fabrics recommend using warm or cold water. New detergents are also available that are specially designed for cold water washing. Modern clothes dryers have an "Optimum Dry" feature that will automatically turn off the dryer when the clothes have gotten "dry enough."
Set your refrigerator and freezer to the manufacturers' recommended settings. The dials are often set at levels that are "too cold," making the unit work harder and use more electricity than necessary, all day long. The U.S. Department of Energy recommends maintaining a temperature between 37 and 40 degrees in the fridge, and 5 degrees in the freezer compartment. Consult your owner's manual for more details.
Also make sure that the door seal is tight -- if you can slip a piece of paper through the edge then you need to adjust or replace it. And filling a milk jug or two with water and keeping it the back of the refrigerator provides extra cooling that keeps the temperature stable and reduces the need for additional cooling and electricity use.