These tips are basically to enlighten you on some of the surprising things which are norms in the U.S. Read this site to see the customs of the Americans which are treated as offensive acts in other countries.
It is a norm in America to tip in any place that you have been served singly. Failure to do so then you will be seen to be so ungrateful and very rude. While you are in other countries, you should never attempt tipping as it will be considered to be offensive and disrespectful to those serving you.
In America, if you are in a taxi, you are not allowed to sit in the front with the chauffeur. This is not normal in other countries, and they consider it to be so invasive. In other countries when you sit at the back it will symbolize that you are taking yourself to be superior to the other person in the cab.
You can involve more than one person in bill payment while in the U.S. There is no splitting of bills when you are in other countries for example in France. You will have to decide on who to do bill payment for the whole lot.
Using the left hand is the fourth social custom that Americans are used to but unacceptable in the other regions. In the Middle East and some areas in Africa, sanitary activities were handled using the left hand hence considered to be dirty. In such regions, avoid initiating a handshake through such a hand.
In some of the European nations, the American peace sign custom implies differently than it does when in the US. In such European nations, the peace sign gesture that means ‘we come in peace’ while at America is unacceptable since it derives a meaning like that of the middle finger in these regions.
There some societies in the globe which do not accept the use of the bull horn sigh that is a custom in the US. There is no funny message communicated through the gesture in the other nations like it is applied in the US. It is a communication sign that notifies a man that his fiance is unfaithful in some South American and European countries.
Its not a big issue to refuse a food offer in the US. It may be for the reason that you are full hence you aren’t willing to eat at the particular moment. As party of the culture in Asia, refusing a food offer is disrespectful.