If you are working late or reporting in early, try to meet another employee to ride together and enter or leave together. If you're in a one-person office or store, check with neighboring businesses to see if any of their employees have similar schedules. Don't get in elevators with people who look out of place or behave in a strange or threatening way. Report such individuals to security or the police. Don't use the stairs alone.
Stairwells can be traps as well as a way to save time or get some exercise.
Never enter a stairwell to escape pursuers or potential attackers. Go to an office where there are other people. Be extra cautious when using rest rooms that are in isolated locations. If you bank for your business, vary your route and times of departure. Conceal the bank bag.