Make arrangements with your neighbours to have mail or other deliveries removed from your door. Use a timer to activate lights, and perhaps a radio to make your home appeared occupied. Leave a key with a friend, relative or trusted neighbour to allow them to make periodic checks of your home and perhaps change curtain positions. Do not store ladders and other climbing material outside the building. Please be concerned with lighting in and around your building, particularly entrances.
Good lighting is a crime deterrent.
Allow only tenants access to laundry and locker rooms. Encourage regular meetings with tenants to discuss security. Keep records of all suspicious activities. Make sure you know your street address, not just the building name. Do not announce to a caller that you are home alone.