These days, it seems anyone who’s anyone has their own clothing, cosmetics and sneaker line. Hamish McKenzie delves into the world of celebrity collaboration and finds out what it takes to build your own brand.

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For those of us who exist in a comfortable cocoon of celebrity-indifference, it may come as a surprise to see the extent to which stars’ clothing lines have germinated and multiplied in recent years. Sure, we’re all vaguely aware that various bad-boy rappers have launched their own clothing lines to muscle in on the tough, pistol-packin’ world of retail fashion, but who knew so many other actor-model-whatevers had followed suit.

The people who run www.celebrityclothingline.com, that's who. Thanks to them, fashions by Hillary Duff, J.Lo, Lindsay Lohan, Jessica Simpson, Jay-Z, Mandy Moore, Katie Holmes, Gwen Stefani, Mary Kate and Ashley Olson, and even – for crying out loud – meathead country singer Toby Keith, are a mere click away from registering on your radar. And those are just the ones John Mayer has tried to sleep with.

Then there's 50 Cent.

The rapper, who was once shot nine times, not only has a crazily successful brand called G-Unit Clothing Company, but he’s also about to put out a line of moisturisers and night creams. For reals. (If he expands into hair-care products, maybe he should think about renaming that first album Get Rich Or Try Dyeing.) What sort of a message is that going to send out to aspiring young gangstas? “You can find me in the club, bottle full of bub / Look mami I got the exfoliator if you into skin rubs”? Doesn’t really cut it, homey.

The fact of the matter, however, is that it's a viable form of personal brand extension for these stars. In 2008, that G-Unit clothing line was worth US$150 million to Mr Cent, and, at a time when he's not making much music, it’s an invaluable avenue for keeping his name in the public consciousness. As the economy continues to tank and expensive celebs find less call for their services in movies (for which, according to a recent story in Vanity Fair, studios are slashing budgets across the board) and music (has no one told you it's impossible to sell a CD these days?), they're even more likely to look to fashion as a way to bolster their Name Inc.

The relationship between clothing brands and celebrities is a winning one, says Florence Kong, a business director at advertising agency TBWA Hong Kong. “The celebrities can enhance their personal image, because they look cool and fashionable – and they’re kind of leveraging each other.”

The same is true for Hong Kong stars. Before becoming grossly overexposed in Hong Kong, Batman extra Edison Chen was actually also known for having his clothes on. His streetwear brand Clot, which has collaborated with the likes of Nike, Levi's, and Bathing Ape, reinforced Chen's one-time role as the embodiment of Canto-cool. Actor-director and watch-endorser Daniel Wu is another to have made the leap into fashion, recently collaborating with the hip Knowledge jeans brand. SoftHard's Eric Kot has also got in on the action, setting up his own line (AAAA) and collaborating with Bape.

For celebrities, fashion and image help sell products just as well as their acting or singing abilities. “For fashion brands, I don’t think people are that rational,” says Kong. “After all, fashion is only linked to the image. It’s really about style.”

Thus, whatever bears their name becomes part of their character. “Daniel Wu is an actor, and people know him, so if he has a bar or T-shirt coming out, people will think 'this is Daniel’s thing',” says stylist to the stars Denise Ho, who has years of experience working on shoots for the likes of Vanity Fair (Italy) and Prestige.

Ho says celebrities become brands unto themselves by carefully selecting a style and adhering to a consistent image. “All celebrities have good stylists who pay attention to what they should wear for every event, and people see what they wear and want to buy it. That’s when you become an icon, that’s when you can start your own brand.”

And soon after that, presumably, is when you launch your own moisturiser line.

Read our other fashion features:
The best upper-floor stores
Upper-floor shopping
How to be an INC