In the UK it is rude to point at someone with your finger, it makes the person feel uncomfortable. Being loud is considered rude. It is more important to remember to say please and thank you at the right times. There are many more things but you will find that if you are rude, most British people are too polite to say anything about it! ^_^

Coming to China: 1.If someone asks a question you don't want to answer, then tell them you don't understand Chinese 2.Do bargain if you are shopping in a wholesale or flee market. 3.Do keep all the taxi receipt in case you forget things in the cab. 4.Don't talk to someone who look suspicious to you. 5.Most people on the street are willing to help. But do use simple expressions. 6.Write the places you want to go in Chinese in case you need to ask for directions on the way.