NEW YORK (MainStreet) — Job interviews are nerve-wracking for even the most seasoned professionals, but prepping for them means they can be less stressful.

Depending on the industry where you want to work, in some cases there are still more applicants for the job opening than there are available positions, said Matthew Randall, executive director of the Center for Professional Excellence at York College of Pennsylvania. In short, you don't want to make a seemingly innocent mistakes that you will regret later on.

It starts with your look. While this rule might have been ingrained in you since you were a child, dressing the part is key. You can never go wrong by looking your best by wearing a suit.

“There is an unwritten social norm that states when job candidates show up to an interview, they should look well-groomed,” he said. “Properly dressed candidates communicate to the interviewer that they understand one of the core elements of professionalism, which can help put the interviewer at ease.”

Avoid showing up late at all costs. There may be times when a late arrival is out of your control, but avoid a potential headache by mapping out the route ahead of time or even driving to the office in advance to make sure you can find it.

“The last thing an interviewer wants to start off hearing is a list of excuses,” said Randall. “If something comes up that is truly out of your control, contact your interviewer as soon as possible to explain the situation and possibility of rescheduling. This will undoubtedly be received better than showing up late and wasting their time.”

Just glancing at the company’s website the night before the interview is not sufficient. Research any growing trends that might be relevant, he said. If it is possible, find out why the company is looking to fill the position so you can communicate how you would be the best option to fit that need.

WATCH: More personal finance videos on MainStreet | More videos from Lauren Lyons Cole

View Today’s Auto Loan Refi Rates

“The worst mistake that an interviewee can make is not doing research on the company, its competitive position and how he or she can add value in that specific job to the company as it competes in the marketplace,” said Kevin Burns, who helps place students in jobs as director of the undergraduate business career center at the W. P. Carey School of Business at Arizona State University. “This shows the interviewee is a job acceptor, not a value creator.”

Employers typically ask the candidate at the end of the interview if they have any questions. Avoid the standard obligatory ones or questions which could be answered easily by looking at their website. Instead, use your preparation and that information to develop an educated question that requires a thoughtful response, Randall said.Some job candidates wind up being memorable for the wrong reasons such as glancing at their cell phone, calling the interviewer by the wrong name or failing to answer key questions.

"Although interview blunders may be embarrassing, candidates who can quickly recover might actually turn an awkward moment into a time to shine," said Robert Hosking, executive director of OfficeTeam, a Menlo Park, Calif. staffing company.

Be honest about any skills you may lack or why there is a gap in your employment history.

“If you lie or stretch the truth, it'll catch up with you,” he said.

If you are asked about former employers, be tactful and avoid criticizing past managers or colleagues, which will “only make you look bad,” Hosking said.

--Written by Ellen Chang for MainStreet