1.The luckiest number is eight because it also means "prosperity"
2.Don't stick chopsticks upright into a bowl of rice.
This resembles incense sticks placed into food left for spirits.
3.The unluckiest number is four as it sounds like the Chinese word for death.
Most hospitals and hotles don't even have a fourth floor.
4.White or yellow flowers,especially chysanthemums,are used for funerals.
5.Don't sweep the floor on Chinese New Year's Day lest you sweep away good fortune.
These are some taboos in Taiwan,I hope can share with you.
And I also want to know more about taboos in the forien :)