

Install dead bolts.
Use a door brace for low use doors and in a "safe" room.
All locks should be changed when you move into a previously occupied house.
Don't hide keys anywhere.
Engrave all your property, for traceable identification.
Make a list of all your valuables, including serial numbers.
Consider putting lights on a timer if you return home after dark regularly, including photo sensitive flood lights.
If you will be away for a few days:
Remember, one in four burglaries occur while the people are at home. Physical security like locks and good neighbors or dogs can be easily overcome.
An alarm system will make so much noise that a burglar will not stay, and is unlikely to run off with anything. Once the alarm is sounded, the intruder knows he has been detected and will waste no time in exiting. He is uncertain who has heard the alarm or if security or police are being dispatched.
Of course, if occupants are present at the time, and are alerted, they are able to take precautionary action that could save their lives.