Always lock your home when going away, even on a short errand.
Make sure the exterior doors are solid core wood or metal.
Make sure that you have good dead bolt locks installed on your doors.
Install a peephole viewer in your doors with a view angle of at least 180 degrees.
Secure all of your sliding glass doors with a strong wooden dowel in the door track or a commercially produced product that stops the door form movement.
Secure all double-hung windows with a small bolt, nail or commercially available product to block the window from being raised.
Make sure that walkways and entryways are well lit after dark.
Use timers on lights and set a staggered pattern throughout the house.
Keep shrubbery and trees around the house trimmed back to avoid leaving places for criminals to climb to second stories or hide around windows and doors.
Never hide keys to the house outside. The hidden key trick is well known by criminals.
Should you purchase a new home or loose your keys, re-key the doors to the house.
List, photograph and engrave your valuables. If possible video tape your property and make sure that this information is stored in a safe place off site.