When you meet some of your friends or another person, you raise your hands (or go to them for hand shaking) and say "Hello" to them.
In Thailand, the greeting word "Hello" is replaced by the word "Sawasdee" (pronounce, sa-wad-dee) with a suffix word "Krab" if you are male or "Ka" if you are female to make your speech more polite. So, it will say "Sawasdee Krab" for men or "Sawasdee Ka" for women. How people feel when you say those suffix words may be as same as when you hear the word "Sir" behind a sentence.
Next, what you should do together with saying that greeting word is raising both of your hands, put your palms together (your fingers point upward) and lower your head a little. See this example from the picture in the right.
Now, a little more to make the nice greeting, don't forget to smile! Your smiling shows that you are sincere to greet other persons. Yeah, you have just performed a perfect greeting.
Special Thanks to "http://www.oknation.net/blog/print.php?id=155095" for a lovely picture.