Tips of don'ts to expats on country(ies) of your best knowledge,

Many foreigners do somany terrible mistakes in the sight of locals, because they do not know the cultures and value system of that society. and with this thread i want you to tip some of the things that one should not do while he/she is in your country or country that you know well. i prefer to say tips of don's. Example: Don't kiss on the lip in pulic places in India etc.