A job interview is an artificial process.

The questions are esoteric; the setting is forced; the rules and conventions are convoluted.

Attending an interview is rarely synonymous with how you can be expected to perform on the job or the regular way that the business operates.

But even the best candidate can destroy their employment chances in a job interview.

Often when we interview people who have been in one role for most of their career, it’s apparent they lack so much experience in interviewing that they ruin their chances with potential employers, even if they could be fantastic in a role.

Interviews can easily turn nasty. Here are three of the most common interview etiquette faux pas that I have observed:

1. Being obviously motivated by money

Asking about salary is an appropriate question, if handled properly. When you are asked about motivations to leave your employer, however, crying foul over your pay is not. No employer ever wants to think that a candidate is solely motivated by money. Responsibility, career advancement, opportunity, a better work culture or life balance: they’re all good reasons. They’ll sit well with the interviewer. But relying solely on money as a motivator? What guarantee would the employer have that the candidate wouldn’t quickly up-stumps for a bigger carrot?

2. Failing to engage all interviewers

I’ve been guilty of this, so I’m not preaching from an ivory tower on this one. It’s actually really tricky to engage all interviewers when you are facing a panel. Still, it’s a surprisingly common bug-bear from prospective employers. Focussing your attention on just one person (the person asking the questions, the most senior person in the room, or even the interviewer who just seems to be smiling at you a lot) can cause all sorts of odd perceptions.

3. Acting like you’ve already got the job.

The single greatest mistake I’ve seen people make going into second or subsequent interviews is to assume that they have the position sewn up. If you use assumptive phrases like “I will” instead of “If I’m successful, I would…” you might as well be saying to the interviewer ‘I’ve already got this job, so let’s cut to the chase.”

The truth is that until there’s a signed letter of offer returned to the organisation, the job can still disappear. There’s a mantra I use whenever I’m in that situation, especially when I feel that an interview is going well. “I don’t have the job yet, I don’t have the job yet, I don’t...” – you get the picture.

Interviewing is a learned skill. The only real way to avoid making these kinds of mistakes is to put in the necessary preparation and practice beforehand. Just being the right person isn’t enough.