Report any broken or flickering lights, dimly lit corridors, doors that don't lock properly, or broken windows. Don't wait for someone else to do it. Don't advertise your social life or vacation plans and those of your coworkers to people visiting or calling your place of work. Talk to the building manager about improving poorly lighted corridors and stairways. If you find yourself in an elevator with someone who makes you nervous, get off as soon as possible.
Attackers can hide in stalls and corners.
Make sure restrooms are locked and only employees have keys. Be extra cautious when using restrooms that are isolated or poorly lighted. Create a buddy system for walking to parking lots or public transportation or ask security to escort you. Always lock your car and roll the windows up all the way. If you notice any strangers hanging around the parking lot, notify security or the police.