The rules of cool

Don't make it look like you care too much about your hair

The publication of The Hipster Handbook - a guidebook to the essentials of being cool in the US - has highlighted the difficulties in being - and remaining - at the cutting edge.

The book, by Robert Lanham, stresses that the most important lesson is that "the hipster walks among the masses in daily life - but is not part of them."

Across the globe, the quest to be cool is never-ending, depending on ceaseless advances in trends and fashion.

"There's a different definition of cool for everywhere around the world," said Ruth Jarvis of London's Time Out magazine.

She told BBC World Service's Outlook programme: "Here in London, we're too cool to even care or engage in that discussion."

The rules of cool

Never get angry

Have a cutting edge look in fashion, or dress eccentrically

Have many friends, or you will die alone

The fickle nature of fashion means that the fine line between looking great and looking passé is always easy to cross - not only at different seasons, but in different countries.

In Japan, dying hair the colour of tea is considered cool - while in South Korea, dying hair ever more extreme colours has become so pervasive that to leave it natural - or even to dye it black - is seen as rebelling.

"Hair is an absolute essential," Ms Jarvis stressed.

"It's the fastest thing to change, and the easiest thing to copy.

"The main thing is that it has to look like you don't care too much - that's the whole basis of cool."

Dyed hair, exposed back, and low jeans - Korean definitions of cool

Behzad Bolour, a cultural commentator from Iran, said that in Tehran a similar rule applied: "Your hair has to look unwashed - you position it on the pillow at night in a way that will maximise your curls."

He also said the coolest thing to do was to attend private parties in tight outfits - not street cool but private cool.

But in India, it is essential to be seen outside, and in loose, flowing clothes.

"Too much cool will make you a wannabe," Freishia Bomanbehram, of Mumbai's Red FM radio station, told Outlook.

Coffee shop essentials

However, some things do appear to be universal.

All four of Outlook's cultural correspondents - in Europe, the Middle East, India and South-East Asia - agreed that coffee shops were the place to be seen - and to commentate on everyone else's efforts to fit in.

Fashion shows set the trends for India

"They don't know what cappuccino is, but they have to go," said Mr Bolour.

And, just as some things are cool around the world, some things remain cool through time too.

"Some things aren't going to go out of date - that just-got-out-of-bed-but-automatically-look-cool look," Ms Jarvis said.

"To a degree, basics like jeans and white T-shirts on a good body are never going to change."

And even the Hipster Handbook itself will eventually go out of fashion, Ms Jarvis argued.

"It's a bit of a gamble publishing it alluding to specific bands and specific bars," she said.

"The minute you stipulate those things everybody knows about them and nobody wants to be there any more."

In the end, becoming and remaining cool will always be only as important as the individual chooses it to be for them.

But that doesn't imply a complete absence of effort, said Mr Bolour: "You've got to be yourself - but wear a hat."