One thing every homeowner should do at least twice a year is take a walk around and through your property with a close friend or neighbor who is not too familiar with your house. The purpose of not doing it alone is your pal may spot things you'll overlook. Return the favor and complete a survey for your friend. Chances are good you can tell when your neighbor isn't home. Remember it's a burglar's job to know the same things.
Most professional criminals can tell nobody's home at least four or five houses away.
Several dead giveaways are always closing the drapes ONLY when you're not home. So are closing up the house as tight as a drum in the hot summer months without the air-conditioner running. Turning on a certain light or two and every other room is in total darkness. Ditto for picking up all the kid's toys, taking in the dog, shutting the garage door if you frequently leave it open, and turning off the lawn sprinkler. If you use an answering machine never leave a message that you're not home.