Before showing any gesture in a foreign country, make sure it is harmless
For example, while in Brazil, you should forget about the OK gesture. There, it means roughly the same as the middle finger does for people in our country. If you want, say, to thank the staff of a Brazilian hotel, showing them the OK sign would be as ridiculous and offensive as giving a girl a mole repeller on a first date.
If you are heading to Greece and plan to eat at restaurants and cafes there, you should forget about the stop gesture – that is, a hand held out with the palm facing outward. In most countries, this would mean you are full and grateful to the staff, but cannot eat another bite. However, to a Greek, you will show that you are extremely dissatisfied with them and their food.
Travelers heading to South America, West Africa, or the Middle East can be let down by thumbs. More precisely, raising them in the 'great' gesture. Of course, we've all heard that at one time the raised thumb was a sign that the life of a Roman gladiator should be spared during combat. But in fact, it was not the thumb but the raised fist that could show mercy. In any of the above regions, this gesture will mean a very unpleasant intention toward the person you show it to. So be careful, and if you are a fan of raising thumbs up, it's best to bring an electronic dog repeller, because they will set the dogs on you for it.
Tourists heading to China, Thailand, or the Philippines should know that licking the plate to show delight in the food is not advisable. Leave some food on the dish, and you will show that you are full and grateful.
As you can see, every country has its own rules. So be sensible and learn as much as possible about the features of the place where you plan to vacation.
_