Back in his school days, Mr Stephen Bayley received a report from his headmaster that read, “Charm alone will not get him through.” And yet, it hasn’t exactly held him back. He went on to co-found the Design Museum and was the person for whom the appellation “design guru” was invented. His 2014 book on the subject, Charm: An Essay (What Money Can’t Buy), features a quote on the cover from the author Mr Will Self, which says, “Stephen Bayley can charm your pants off – he charmed mine off and returned them to me dry-cleaned and pressed.”

Ms Audie Charles, creative director of Anderson & Sheppard, has dressed some of the world’s most charming men, including princes and kings, movie stars and literary giants, both in her work for the Savile Row tailor and when she worked for the legendary 1960s tailor Mr Doug Hayward. “Charm is a kind of magic that casts a captivating spell on others by the way you dress, speak and behave,” says Ms Charles. “No matter how cross you are, someone who is charming can put you at ease and make you laugh.”

Charmers win life’s prizes without seeming to try. Charm, said the French philosopher and author Mr Albert Camus, is “a way of getting the answer ‘yes’ without having asked any clear question”. Charm is easy to detect and yet devilishly hard to define, which is what makes it so fascinating. Luckily, our experts are here to explain one of the most seductive and elusive powers known to man.

At its heart, charm is about empathy and being considerate and understanding of others, no matter who they are. “Good manners and being nice to everyone you meet is always a good start,” says Mr Bayley. “Assume you have secret knowledge that every single person you meet will soon become very rich.”

“Doug Hayward always made a point of remembering the birthdays of his clients’ PAs,” says Ms Charles. “He’d say to them, ‘Is he treating you well?’, ‘Oh, he’s so lucky to have you,’ and ask them about their holidays and so on, which ultimately made for a better relationship with the client.”

“Be yourself, but a nicer version,” says Ms Anda Rowland, managing director of Anderson & Sheppard, who gives the example of Prince Charles as someone with a gift for charm. “When he visits us, you can feel a palpable change in the atmosphere. That’s because he takes care to talk to everyone without too much ceremony. He’s genuinely interested and makes everyone feel important.”

Charm applies not only to people and behaviour, but also to places and things. It could be argued, for example, that a cosy cottage is more charming than an oligarch’s apartment. But why?

“The question of accident or design is fundamental,” says Mr Bayley. “We rarely find over-designed objects charming and in products and buildings, we tend to prefer the whimsical to the over-wrought.”

We can apply this idea to fashion and the way we dress, believes Ms Rowland. “For me, mass luxury lacks charm because you don’t have the feel of the maker,” she says. “It’s not made for an individual and so lacks that human element. Charm has some element of personalisation and individual thought.”

“Clothes that have been worn and loved have more personality to me,” says Ms Charles. “Frayed shirt cuffs, well-polished shoes, which have been fixed and repaired, have a lovely quality to them, much better than brand new and gleaming.”

“A man who doesn’t care about his appearance probably doesn’t care about much at all,” says Mr Bayley. “There should be a lightness and judgement to it all. It should, they used to say, take 10 minutes before you realise someone is well-dressed. It might take as long to realise you are being charmed.”

Charm is really just the ability to make someone enjoy your company. Anyone who has enjoyed themselves at a party or whiled away an afternoon in a nice restaurant drinking wine with a new friend has both been charmed and is a charmer. Many aspects of charm can seem quite broad and hard to define. But never complaining, ever, is one of the cast-iron rules of charm.

“Self-deprecation is a far better ad for yourself than moaning or mouthy show-boating,” says Mr Bayley. “Assume any fault anywhere at any time to be your own, irrespective of its cause.”

“There’s nothing worse than a man complaining about where he’s sat at for dinner,” says Ms Charles. “There’s a saying: ‘Those who care don’t matter and those who matter don’t care.’ Making a fuss is the total opposite of charm.”

“Be curious and inquisitive, but not intrusive,” writes Mr Bayley in his book. “There is absolutely nothing that people enjoy more than the suggestion you find them fascinating. Listen. Be quiet rather than loud, but, at the same time, do not be timid.”

Charm is in short supply in much of today’s politics, but it is the former British prime minister Mr Benjamin Disraeli who shows us the true definition of charm. Lady Randolph Churchill, Sir Winston Churchill’s mother, once made this comparison between Mr Disraeli and his great rival, Mr William Gladstone: “When I left the dining room after sitting next to Gladstone, I thought he was the cleverest man in England. But when I sat next to Disraeli, I left feeling that I was the cleverest woman.”

The great politician-cum-socialite, who befriended and charmed Queen Victoria, was one of the masters of small talk. His maxim, “Talk to a man about himself and he will listen for hours”, is as relevant as ever.