When travelling to other countries it is important to consider the cultural implications of what we do. Gestures can mean different things. What we do as a matter of course could insult someone else. Take the okay sign, thumb touching index finger, in Brazil it refers to an intimate part of the body and in Mexico to sex, in France it means zero.
In Vietnam showing crossed fingers is considered an obscene gesture, especially if you are looking at someone. When handing something to a Japanese person you should always hold it in two hands as if you are presenting it.
In Greece, an upward nod of the head means no and turning the head to the side is yes. In India people use a head "wobble" for a variety of responses, could mean yes, it could mean they acknowledge you and it could be "thank you".
Eye contact is important in Arabic countries and a sign of respect, but in Japan you should avoid giving too much eye. In Nigeria and Thailand children are told to avoid eye contact with adults.
In Fiji you could find yourself holding hands for an entire conversation, pulling your hand away is considered rude and insincere. In Asia do not touch people's heads, Buddhists consider it the most sacred part of the body.
What we wear can also give rise to insults. Leaving body parts such as your legs or upper arms bare is definitely not on in Muslim countries – for men or women. When visiting churches, mosques, synagogues and other places of worship you may be expected to cover your head, shoulders and/or legs. Most places will provide wraps and scarves to cover up. In Buddhist countries being covered from shoulder to knee is best.
Public displays of affection are also taboo in many countries, no matter how modern it seems. People have landed in jail for being too touchy. Holding hands is normally fine, but save the snogging for behind closed doors.