1. If somebody politely asks you for help (e.g. car crash), refuse at least two times.
2. Don’t make somebody lose their face by randomly spraying acid around.
3. It is impolite, not to spit and urinate in public (drink a lot of water).
4. Do not point out that most items were copied from Western countries (e.g. road signs, electronic music, toenails) but emphasize that China has invented a lot of great things (tea, gunpowder, fingernails).