How To Describe Beautiful In Chinese For Someone

My one student(boy) was always curious as to how to tell someone(girl) that she looks  pretty or beautiful in Chinese.

Here is the useful expression :

1.you are pretty.
你很漂亮
ni hen piao liang.

2.you are so cute
你很可爱
ni hen ke ai

3.you are beautiful
你很美丽
ni hen mei li

So try to practice them when you happen to pretty girls.