If you are a new arrival in Hong Kong, or have not lived in Asia, and want some good advice on fitting in, may I suggest you purchase a copy of this book:
Hong Kong Life & Culture: A quick and easy guide for Expats and Visitors
Written by Emily Chan
It will give you an insider look at Hong Kong culture, as well as providing some useful tips.
Get it at most bookshops, or order it online.
But read it, and enjoy Hong Kong.