Whether you realize it or not, your outfit says a lot about you before you even get seated to begin your interview. To take it a step even further, your color of choice to wear also speaks volumes. That's why it's important to pick the right color that will convey the most accurate message that you want to get across to your prospective employer.
The best way to express your genuine interest in working for that company during an interview is to ask the employer some thought provoking questions that shows that you've done your research on the company and want to be sure that it's a good fit for you as well.
Even though your interview is over, this time period still leaves room for the employer to evaluate whether you're a good fit, depending on your follow up actions. This is a crucial time as it could make or break whether you're given a job offer.
You must sell yourself in the interview so that the employer walks away feeling like you offer something unique that they need. One way to be sure that you "seal the deal" in the interview is to prepare yourself before the interview occurs.