The most qualified person doesn't always get the job. Sometimes, the person who gets hired is the one who handles the process of applying and interviewing for a position better than the other candidates.

You may be the most experienced and the person who would perform best if hired, but there are lots of ways to derail your own candidacy. in fact, even if you have everything needed to get hired, there are errors you can make that keep you from even getting an interview.

Each one of these may seem like a small transgression, but any one of them can be enough to ensure you don't get the job. Not making these mistakes doesn't take that much more effort than making them, so if you're in the market for a new job, putting in just a little more effort can be the difference between success and failure.

A man looks up at a blackboard decorated with question marks.

Sometimes it's not a mystery when you don't get the job. Image source: Getty Images.

Not customizing your cover letter

Back when I was working as an editor hiring reporters, every job we posted would get dozens of responses on the first day. Our job postings were not generic. They listed specific demands for the beat being hired for.

Many of the cover letters we received, however, were generic. They laid out the candidates' qualifications for a reporting job, but not this specific reporting job.

Do something in your cover letter to make it clear that you're applying for this specific job and not merely sending your resume to every ad you find. Address points in the job posting, ideally ones that won't be evident on your resume, and make it clear that you put effort into the application process.

Don't be late for the interview

The correct time to arrive at an interview is about five minutes before your scheduled appointment. To make sure that happens, you'll want to scout the route beforehand and know exactly where you're going. You'll also want to plan for traffic and budget time for any problems that may come up.

If that means you have to camp out at a nearby coffee shop or sit in your car beforehand, that's fine. Being late, even a tiny bit late, can cause the person doing the hiring to immediately doubt your reliability. That's never a good thing, and it can kill your chances of getting hired.

Dress the part

Once, when I was hiring a truck driver for my family's ladder and scaffolding business, one candidate entered the vestibule of our office shirtless. He was carrying the polo shirt he intended to wear -- ostensibly, we assumed, because it was hot that day and he wanted to avoid sweating.

What he didn't realize is that our entrance was glass-lined and everyone, me included, could see him. That bit of embarrassment added to the fact that jeans and a polo shirt are not interview attire.

When you go to an interview, unless otherwise instructed, men should wear a suit and women should wear something equivalent. Anything less makes it look like you're either not taking the process seriously or that you don't know what appropriate attire is.

Not sending a thank-you note

On a few occasions, I've interviewed multiple people and been undecided between two of them. When that happens, an easy way for one candidate to lose the job is for him or her to not send a thank-you note after the interview.

This does not need to be a long note. It should be a simple thank-you that perhaps clarifies a point made during the interview. Ideally, it will be handwritten and mailed, but email is fine, too, if that's how the candidate and hiring manager have been communicating.

Every little bit helps

It's possible to make one or more of these mistakes and still get hired, but why take the risk? Do the little things right and you'll maximize your chances of getting the job.