1) They try to take advantage of every dollar they spend on their education. It could be anything including having excess food in a restaurant if the price is cheap.
2) They do not speak up their mind when they need something. This result out to be not so beneficial as they miss out many opportunities that cross their path during their time at the University.
3) International students many times becomes too much emotionally involves in relations or groups, which limit their interactions with other groups and peers thus narrowing the scope of their social life.
4) They set their expectations low. Sometimes students perform poorly in their academics, which as a result affects their self-esteem. They come to a conclusion that in US education systems it is tough to perform better.