Improve the insulation in your home. This can include major upgrades like new roofing, added attic insulation, and thermally-insulating windows. But it can also include elements as simple as ensuring doors and windows are closed when heating or cooling, and that adequate weatherstripping seals leaks.
Increase the performance of heating, ventilation, and cooling (HVAC) systems. Again, this can be as substantive as installing an energy-efficient furnace or a solar hot water heater, but it can also be as simple as turning down the thermostat in winter and turning it up in summer. Also, reduce the heat load during summer afternoons by moving laundry and baking to cooler hours in morning or evening.
Reduce lighting costs. Replace inefficient incandescent bulbs with compact fluorescent lights or light-emitting diodes. Install smart lighting controls to illuminate only when and where necessary. But don't overlook the simplest energy saving strategy for lighting: turn off unused lights.
Eliminate "electricity vampires." Many appliances use electricity even when "off." Televisions, DVD players, and cable boxes all use standby power. By plugging them into a power strip then turning off the power strip, you'll reduce electricity going for standby power. In addition, laptop computers, cellphones, mp3 players---all sorts of electronic devices---use a small transformer to charge their internal batteries. These transformers are drawing power even after charging is complete---unplug them, slow down the meter.
Re-evaluate your overall energy usage. Do you have a second refrigerator in the garage holding just a 12-pack of beer? At 7 PM are three different televisions going in your house? Do you run the washing machine for two pairs of pants and a shirt? See where you can modify your habits and reduce your energy usage.