There's a pretty common checklist for anyone seeking a new job. You get your resume and cover letter in order first. Then, when the interviews start to come, you make sure your suit fits, your shoes match and your hair is cut.
There's no secret to the fact that you need to present well in an interview, regardless of how skilled and experienced you are. Of course, these tips aren't even tips any more. They are nothing more than the price of admission to the job market.