It's a depressing fact that interviewers apparently make their mind up about candidates within six minutes of meeting them - and that first impressions matter even more than a candidate's education, professional qualifications or references.
However, it's not always clear just what assumptions are being made about us on the basis of our hairstyle, clothes or shoes. It's a fair bet that a facial tattoo will put you out of the running for a job as a corporate receptionist, for example, but what about more subtle aspects of your style?
Many recruiters admit to making assumptions about candidates - sometimes very cruel ones. We look at a few of the commoner prejudices.
Nobody knows the origin of the phrase 'no brown in town', but it seems it still applies. A study by the government's social mobility commission recently found that candidates from less advantaged backgrounds were being discriminated against by investment banks.
And one of the clues that interviewers look for is shoe colour - with only black being acceptable with a suit.
"For men, the wearing of brown shoes with a business suit is generally, though not always, considered unacceptable by and for British bankers within the investment banking, corporate finance, division," read the report.
The wrong suit
You might think you've got it right with a dark suit, plain shirt and black shoes - but there's a right and a wrong way to wear that suit. Etiquette guide Debretts, for example, advises that the bottom button of a single-breasted waistcoat must always be left undone, and that a belt is never worn with a waistcoat or double-breasted suit. Your suit jacket should have three buttons on the cuff - never more or less.
Like the black shoes, the right suit is a subtle signal that interviewers in the finance industry look for to try and make sure you come from the right social bracket. You might want to consider whether you really want a job with an organisation like that.
New York recruiter Bruce Hurwitz recently caused outrage when he suggested that women should ditch the engagement ring when they go for a job interview.
"When a man sees that ring he immediately assumes you are high maintenance," he writes. "When the woman at the office who has the largest diamond on her finger sees that ring, she will realise that if you are hired she will fall to second place and will, therefore, not like you. Lose the ring!"
The post has, unsurprisingly, been widely criticised, with Grace Killelea, founder and CEO of Half The Sky Women's Leadership Institute commenting that his advice was 'ridiculous' and 'makes women sound petty and small'. Other senior businesspeople have agreed.
It seems likely that Mr Hurwitz is simply describing his own prejudices - prejudices that may not be widely shared.
There's a big difference between the way people with tattoos see themselves and the way employers see them. While 8% of tattooed people think their ink makes them look more intelligent, a Harris poll found, 27% of people without tattoos think they make a person look less intelligent. People with tattoos are also perceived as less attractive and less healthy.
All in all, while a tattoo won't stop you getting a job altogether, it may make it harder to aim terribly high.
As Joanne Blake, president and owner of Canadian corporate image consulting firm Style for Success, says, "Despite how mainstream they are today, tattoos have historically become associated with prisoners, gang members, and other types of people who aren't upstanding citizens."
More than half of men in Europe now have a beard, says Braun - but they may be making it harder for themselves to get a job. Research from the Aziz Corporation has revealed that 40% of business directors believe beards can appear untidy. Bearded men are also perceived as being likely to put their home lives ahead of work.
Comments chairman Khalid Aziz, "Even if these are the only people who hold these prejudices, having a third of your potential customers see you as untidy should cause any businessman serious concern."
A survey last year revealed that an astonishing 50% of British companies are less likely to hire job applicants if they're overweight. Obese workers are perceived as 'lazy', 'unable to play a full role in the business', and 'unable to do the job required'.
The best answer is to dress as professionally as you can, keeping your outfit simple but smart - and make it clear through your interview that you're anything but lazy.
The UK's 10 best-paid jobs
The UK's 10 best-paid jobs
Flying high literally as well as metaphorically, pilots top the salary scale this year. There are various routes into the job, from university courses to airlines' own training schemes; private training will set you back as much as £50,000 to £60,000.
"I most enjoy the variety of the job, working as a team, to a schedule, with the responsibility of safely transporting hundreds of people to their destination. I would advise aspiring pilots to thoroughly research training routes, understand the serious financial outlay required with no guarantee of a job after training and to consider other routes such as flight instruction."
Not all CEOs are making millions - but they're doing pretty nicely on average. There's no clear route into the job; an MBA can help, but many bosses have worked their way up from the bottom and many simply started their own firm.
"There is an old saying, it's very lonely at the top, which is usually the case for a CEO. You're the leader and you're responsible for everything, meaning you take the credit for the successes and feel the most pain for the companies' failures."
Most air traffic controllers train through National Air Traffic Services (NATS), which has programmes for college leavers who have studied at BTEC ND/HNC/HND level, university students on a sandwich year and graduates. NATS says the most important attribute for acceptance on a course is natural aptitude.
"Much of the time, the job is routine and capable of being done by many people. What you are paid for, however, is your ability to make the right choices and decisions under extreme pressure."
The high pay reflects both the heavy workload and the length of training required - a five-year degree course in medicine, a two-year foundation programme of general training and then another three years specialist training.
"You will get paid well and (despite recent changes!) you will get a very good pension. You will, however, work hard for your money with less recognition than previous years."
This is a job where most people work their way up, although qualifications like the Chartered Institute of Marketing's Professional Diploma in Marketing or the Institute of Direct and Digital Marketing's Diploma in Direct and Interactive Marketing can help. You'll probably need three or four years' experience before you can move into management.
"It's great working in such a varied job - there's something new every day. I enjoy the travel, too. But it's fast-paced, very hard work, and there's a lot of technical data analysis work involved."
It's not surprising that IT and telecoms directors earn good money. The job requires both business and technical skills, and the stakes are high: smoothly-running IT systems are crucial for most businesses and the cost of getting things wrong is high.
"It's a high-pressure job, and the hours can be unbelievably long, but it's extremely rewarding when a project goes well. The biggest problems are staying on top of changes in technology and being clear about what's actually achievable within a budget."
Financial managers and directors need to be qualified accountants and, particularly in larger organisations, have strong general business skills. And the job carries huge levels of responsibility, from keeping the company in good health financially to making sure it complies with the law.
"What I enjoy about the job is the way it's central to the business, the way I'm involved in creating long-term business plans. Compliance [with regulations] can be a bit of a pain; it takes a lot of hard work."
Until recently, the only way to become a senior officer was to work your way up through the ranks. Each police force sets its own recruitment process and selection policy, though there's a basic national framework for evaluating competency. This year, though, the College of Policing has started appointing superintendents from outside the force - so you might be in with a chance.
"I love the opportunity to take on a vast array of roles which would never be possible in a civilian organisation and to progress through a clearly defined promotion structure, should I prove to be good enough. The training I have received has been quite brilliant, enhancing my life skills as well as my ability to do my job well."
If your vision of a bank manager is of a middle-aged man in a panelled office dictating stern letters to his secretary, think again. It's now about managing a team and, especially, attracting new customers and monitoring branch performance. There are two ways to get to be one: either through a bank's graduate scheme, or by starting off in a customer service role and working your way up.
"For me, what's great about working in a branch is that anyone could be a branch manager, you don't have to have a certain skill set. Having a background in customer service, whether it's in a bank or with another retailer, certainly helps. Some other skills that would help are organisation, patience, tolerance and empathy. After 27 years I can genuinely say that that not only do I love coming to work every day, I have also made lifelong friends here. For me, it's not just a nine-to-five job."
Once you're qualified as a teacher, it's a question of working your way up by gaining extra responsibilities - by becoming a head of department, a head of year, or a specialist in something like special educational needs. At head teacher level, the job is far less about teaching itself, and far more about managing staff and budgets and creating a productive, disciplined learning environment.
"It's a common complaint that teaching is all about performance targets these days, and there is some truth in that. It's a question of balance, though. The most rewarding part of the job is knowing that you're bringing the best out of every single child by creating an environment where they feel safe and motivated to learn."