How should a graduate student email a professor from another country in order to get feedback on their work? I'm trying to contact with a professor from another country to ask him to see my work and send me a feedback. But I don't know what is better to say that, someone told me that I must "sell myself" and tell that Prof. how   awesome I'm and someone told me that just be abbreviated and be direct to the subject. I don't know which one of them is correct, I think about that and  I'm getting confused; for the first opinion, I think that professor meets many people who are more awesome than me, and he is done of looking for awesome people, instead he is looking on awesome work. And for the second opinion, I think I will make that professor feels in a negative way.

As  academics what do you think is the best way for a fresh graduate(Bachelor holder) to contact with a professor who I don't know personally?
Most professors, particularly well-known ones, get tons of such requests. And silently drop them into their recycle bin. They are busy people, with too much on their plates already, to go reviewing stuff that doesn't do them any good (reviewing a paper for a conference/journal, or a thesis, is part of their work, and not to be avoided; this is just work for nothing).

Get somebody in your environment to check over your work, they will tell you if it is any good, help you polish it and present it to where it will be looked at.