Lighting is a Good Bet
Lighting in and around your home is one of the most effective deterrents to keep your home secure. To be effective, lighting must be adequate enough to cast full shadows. The idea is to keep the home well lit so if an uninvited guest should start prowling around, they can be easily seen.
The reason for this is that thieves want to be unseen and the quieter the better. After lighting a little yappy dog is the next best option.