I have been interviewing candidates in IT last month. Here are some of my thoughts. Hopefully, it can be helpful.
1. The resumes of most junior-level Chinese needs improvements. It is worthy of it to ask for professional help if necessary. A good resume won't land you a job, but it helps to pass the initial screening. Make sure a). the format is eye-pleasing and easy to identify your strength. b). no apparent grammar mistakes, c) correct spelling on any terms in CS and related technologies. People won't expect you really know it if you can't spell it correct. It is even more important if the job requirements specifies detail-oriented.
2. Be proactive and enthusiastic. But make sure not to speak too fast unless your spoken English is almost like native. Effective communication. The point is to be effective.
3. This can be a separate topic. I will just give a brief thought here. Many candidates know something here and something there. The problem is if the interviewers ask a question a little bit deeper, the candidates would have no idea at all, not even an educated guess. The better approach is that you focus on one area and make yourself really good at it.
For example, if you want to a system admin, you don't need to know OOP well. On the other side, if you want to be a developer, you don't need to know much about system and network. Also, focus on one language, either C++, Jave, or Python, or whatever.
For a candidate for developer, the worst thing is that you know something about every of these OOP languages, but you don't know any of them well.
Also, make sure you know a language more than its syntax. Study why a feature is needed, how to use it effectively, and if possible, how it is implemented, and are there any other ideas to implement the same feature, etc. A simple example is garbage collection. There are many other topics like dynamic binding, lazy binding, etc.
If you are fresh out of college and graduate school, make sure you are clear on what you did in your projects or thesis. If people feel that you don't understand your thesis or projects well enough, you wouldn't think you are smart and have potential.
Don't exaggerate your resume so much. It could give an immediate negative feeling to the candidate if the interviewer found it out. A live example. One candidate said he was an expert in C++. But he couldn't tell what is the point of having virtual function. That is simply an immediate OFF signal. Another candidate claims he is very good at J2EE. When I just mentioned J2EE is unnecessarily complicated, he said that it was not complicated at all if you knew design patterns. So I continued the topic on design patterns and found out that MVC was the only thing he know. He even put refactoring as one pattern. That didn't give a good impression to the interviewers.
One more note: if you want to be a developer, study design patterns. It helps to understand OOP. GOF book is a little bit hard if it is the first design pattern book to start. Try a relatively easy one.