Entrances should be visible and the exterior well-lit. Thieves don’t like to be seen. If a home’s doors and most-accessible windows are visible from the street or a neighbor’s house, they might look for another home.
Most homes have outside lights; make sure those lights are positioned correctly. Lighting up the front door and driveway is great, but what about the dark corner of the yard near the living-room window? Use motion-sensor lights in these areas.
Exterior doors must be metal or solid-core wood. A particle-board or similarly weak door will break long before most locks give out.
All exterior locks should have dead bolts with metal strike plates. Dead bolts alone don’t deter burglars. Without a heavy-duty metal strike plate screwed in the door frame to receive the lock, someone could break open the door by busting through the wood.
Watch for old sliding-glass doors. Old doors with worn-out rollers can be lifted off the track, bypassing any lock.
Any fence gates should have locks. Yes, burglars can climb over most fences, but they risk more exposure by scaling a fence instead of quickly walking through a gate.
Look for “painful” landscaping. A good way to discourage a thief from breaking in through a first-floor window is to install a rosebush or other thorn-covered plant under it.

You can’t keep a determined, professional burglar out of a home. However, you can make it less appealing for him to try.