Do your part
Leave your outside lights on at night. If your neighborhood is dimly lit, ask your municipal authorities to add streetlights or replace existing bulbs with ones of higher wattage. Leave one or two lamps on inside your house when you're not at home.
Reliable dead-bolt door locks and sturdy window latches help prevent break-ins.
Trim the hedges
Tall hedges provide hiding places for would-be burglars. Keep yours trimmed so that they're no higher than your windowsills.
Peepholes with magnifying lenses let you see who's at your door - without opening it.