The following measures might be useful: -
a) Avoid wearing excessive jewelleries or valuables;
b) Avoid going to notorious place. For example, unlicensed pub,
illegal entertainment outlets, mess etc;
c) Avoid isolated place, road and carpark;
d) Be wary of suspicious persons and leave immediately when you
sensed trouble;
e) Go with your friends;
f) Call Police or Singapore Embassy for assistance when you are
in trouble.
h) Locked your car doors when you need to stop your vehicle.