The most basic error most job applicants make is they think the job interview/resume is about them. It isn't, it is about the employer (hiring manager).

Many people think a resume/interview is about showing how good of a worker/person they are. Instead ALL hiring processes are about how you will fill a specific need of the interviewer. Teasing out what the interviewer is looking for is everything. You shouldn't be thinking about yourself at all or how to make yourself look good, you should be actively thinking about what the interviewer wants and is looking for, well assuming you want that job anyway. Once you understand what they want the rest is trivial, well again if you actually have anything close the skills they want.

Oddly this is much harder than it ought to be, and to a great extent much of the blame is on the hiring manager or HR. After all, their most basic and first task is to accurately and thoroughly define what the position expects. This isn't a simple task, but it *is* the one they have been assigned. Their task isn???t helped by people who spam resumes thinking that is the right strategy, but there needs to be some kind of internal test that assures serious applicants will genuinely understand what is expected.

If you don't belive me, read the average job advertisement, try to imagine the job it descibes. Now go and look at the actual job.