Avoid walking on dark or deserted streets. Avoid taking shortcuts especially through parks or alleys. Be aware of cars that pass repeatedly. Maintain some distance from buildings or parked cars. High heels may be a defensive weapon in some circumstances but they are not good for maneuverability.
Tight clothing can also hinder mobility.
Scarves and long necklaces can provide an immobilizing stranglehold. Try not to become laden down with packages when shopping. Keep your hands as free as possible. Carry a loud whistle to draw attention, if necessary, attached to your wrist - never around your neck. Be alert to the area around your car before you walk to it.