Keep your garage door closed during the winter so cold air doesn't penetrate the outer walls of your home.
Use low-wattage lights outside. Several low-wattage fixtures use fewer watts than one floodlight. Or consider solar-powered lights.
Plant trees that shade your home to keep cooling costs down. Leafy trees shade best on the south and west sides. Deciduous trees that lose their leaves in the winter keep you cool in the summer from shade and warm the house in the winter by letting in sun. Plant evergreen trees to serve as wind breakers.