I've been learning korean with Mrs. Seo, Korean local teacher that teachs in Keimyung Language Institute (KBLC) in Jakarta area, so here are some expression that is useful for tourists that I have learned and wanted to share...
1. Annyeonghaseo
This expression have many meanings, including hello, good morning or expression that is commonly used when the first meeting with other people. This expression is useful when we are entering a shop, it creates sense of friendliness to local koreans.
2. Kamsahamnida (Thank You)
This expression means 'Thank You'. Just like in other country, as a tourist, we need to thank local people especially in shops, hotels, airport, and other local places. When you started to use this expression to local korean, that korean people will have a good impression on you and they will be friendly with you!
3. Igeo / Geugo / Jeogo Olmaeyo? (How much is this / that ?)
This expression is very useful especially when you are dealing with sellers in shops, cashier or supermarket's employees.
4. ____ Juseyo (Please give me some ____ / Please _____)
This expression is very useful. Especially when we are in supermakets, phoning the hotel reception, or in shops and street sellers. When it's hard for you to mention the name of the things that you wanted, just point and say 'Igeo/Geugo' which means 'this/that', they will catch what do you mean easily! :)
Here I included my own video that was made by myself about reading tutorial based on these 4 Simple Expression, this might help for all of you :)