All cultures have their own taboos, but Chinese culture can be very alien to who we were raised in the West. Therefore, if you are planning a trip or stay in China, keep in mind some of the Chinese cultural taboos more frequent, so as not to screw up or pass bullets.
Between the taboos in China one finds calling someone with the index finger, the most classic thing from parents to children, from teachers to students, in the whole of the West. But not in China. It is quite pejorative because it looks like you are calling a dog. Another thing that you should not do is, when giving, give something with a point and to cut, that is, no knives or scissors. The reading that Chinese can make of this is that you intend to cut the relationship or bond.
Four is a unlucky number, in China and also in Japan, so try to avoid it in your gifts. It is that the pronunciation of the number is that of death too, so this is where the taboo comes from. Nor would it be very correct to give a watch as a gift, since the Chinese words for "give a watch" sound like others that have to do with a funeral ritual. Clock, time running, time running out ...
In short, as you can see, it is basically about thinking that the Chinese are susceptible, so nothing to give away with four and watches and nothing to point or point. At least these are some of the cultural taboos in China.