Have home security system professionally installed that offers a 24-hour monitoring system. Make sure to post the home system stickers and window decals–this should alert and deter would be intruders.
Never stop mail or newspaper deliveries, it signals that you are away. Have a neighbor pick up all deliveries if possible.
When recording your answering machine message, do not state that you are not home or out of town.
When leaving for an extended period, put lights and stereo or television on a timer to give the appearance that someone is home.