How to conduct an interview that David Letterman would be proud of

The job interview. I've been on both sides of the interview desk a number of times in my business career. But I'm sure we all remember that very first job interview, fresh out of college or school, feeling a little green, nervous and picking at our unusually smart clothes.

But spare a thought for the poor interviewer. He or she has a great deal of responsibility too. Ensuring the whole thing runs smoothly for one, but ultimately ensuring that they select the right person for the job.

I'm very happy to admit that I like it much more on the business side of the desk. And I think I've learned a lot about how to get the best out of the time allotted and your candidates - sometimes through mistakes. Yep, sometimes it's not the prospective employee who walks away from an interview thinking: 'I really didn't do myself justice in there!'

So, based on my experience, here's what I think helps make for a good interview.

1. Preparation, preparation, preparation

You can never be over-prepared. Your ideal candidate is likely to have spent considerable time looking at your website, possibly checking your social media presence and even looking for news stories on the web. You need to have the same diligence.

I'm not suggesting stalking your potential employee on the internet - although a number of companies do check Facebook and Twitter when considering candidates. I'm talking about knowing what qualities you're after, the skillsets and experience needed to do the job and, of course, what questions you need to ask to get the answers you're looking for. That includes any potential follow-up questions as well as being prepared for any questions they may ask, for example, being able to list any employee benefits you offer.

I try to make sure I have everything I need and the candidate needs. I've been tripped up by a candidate who brought along a presentation on a USB and asked for access to a laptop.... believe me, it doesn't show your company in the best light if you have to desperately search for things.

And don't forget your room. Is it too cold, too warm, too noisy, not private enough? And if your candidate is disabled, make sure it's both appropriate for their needs.

2. Interview format

Decide how you're going to conduct the interview. Who needs to be there? Do you need a member of the HR team (if you have one)? Departmental manager? It may sound obvious, but don't overload your side of the desk unnecessarily. Your candidate will likely be nervous enough without coming in to what looks like the prosecution in a court room.

Make them feel welcome by being friendly and putting them at their ease. I tend to introduce everyone first and explain what they do and why they're there.

I also always explain what the interview will consist of - for example, a competency-based questions section, a 10-minute presentation, a Q&A based on their resume, which of my team will lead which section and letting the candidate know that there will be a chance for them to ask questions, although I always invite them throughout the interview.

3. Conducting the interview

I've always admired people who can talk off the cuff, striding around a stage like they own it with people hanging on their every word. Now, I'm quite happy to speak in public, but I know it's essential for me to prepare beforehand to ensure I get across everything that's relevant and in a clear and concise manner.

The same applies to interviews. Some interviewers are natural talkers who will let the interview ebb and flow around a loose itinerary (if that's the style of interview you've suggested and explained to your candidate). Others will be so practiced they know all the questions they want to ask, while others prefer a checklist of questions, making notes as they go along.

As well as checking how qualified the candidate is to do the job, I like to use the interview as an opportunity to find out more about them as a person. I've employed people who, on paper, would absolutely nail the job, only to find they leave 6 months later because they're just not a good fit, personality wise, with the rest of my team. In my opinion, having the best-qualified person means nothing if the rest of your team are constantly on edge, finding it hard to work with them, and being downright disgruntled.

Lastly, something I always keep in mind is that even if it's my fourth interview of the day, it's the candidate's first with you. Always treat it like it's your first too. Making sure interviews are spaced evenly throughout my morning or afternoon generally helps me make sure that I'm capable of delivering the same experience to every candidate.

4. Closing the interview

I think this is something that's sometimes overlooked by interviewers. Once the interview's finished, usually with an, ‘is there anything else you'd like to ask?', I remind myself that I'm still on duty here. Though your candidate may have just breathed a massive sigh of relief, a little small talk can be revealing and helps to show their personality when things have just become a little more informal.

I like to thank them for taking the time and trouble to attend. I'm well aware that as much as they may need me as an employer, I also need them as an employee; I'm not the only option out there, so I don't act like I am.

Clearly explain the next steps. Is there a second interview needed? Will they need to do any final tests? Sometimes a tie-breaker may be needed if you're really undecided.

If that's that, tell them exactly when and from whom they should expect to hear something, whether they're successful or not - and stick to it.

What are your top tips for conducting a job interview? Let me know in the comments.