Emma Watson celebrates freedom from Harry Potter with the season's must-have crop

For some, it can be the unkindest cut: not everyone can carry off the close crop that throws cheekbones and jawlines mercilessly to the fore. But, increasingly, going gamine is the must-have look.

Emma Watson, who plays Hermione Granger in the Harry Potter films, became the latest star last week to reveal the fearless style, which takes it name from the French for "urchin". Watson, 20, follows a trail of clippings left by, among others, Carey Mulligan, Cate Blanchett, Michelle Williams and Renée Zellweger.

The dramatic change was interpreted as an attempt to match efforts by her fellow Potter stars to reshape their images for the adult world. Daniel Radcliffe, who played the boy wizard, shed all his clothes in the play Equus, while Rupert Grint – Ron Weasley – got down and dirty in an independent film called Cherry Bomb.

While gamine became the hallmark of the 1960s model Twiggy and, before that, was associated with Audrey Hepburn, it doesn't flatter everybody. Keira Knightley's crop for the film Bounty Hunter was met with disapproval by the style police, as was Sienna Miller's cut for Factory Girl.

"Crops tend to work best on oval faces," the celebrity stylist Lee Stafford told Elle magazine, which concluded that Watson's pixie look "gives her a striking resemblance to Mia Farrow". The magazine advised that crops are "fresh, fun and a great way to survive summer heat".

But Carey Mulligan, nominated for an Oscar for her role in An Education, told The Independent on Sunday in February that she didn't like it and couldn't wait for it to grow out. Her problem was that with so many award ceremonies to attend she kept having to crop her hair back rather than show up with it at an "in-between" stage.

Watson has few such doubts: "Cut my hair off a few days ago," she Tweeted. "I love it. It's the most liberating thing ever. I missed all that experimentation that most teenagers go through. I've wanted to do this since I was about 16, so as soon as I had the chance I was like, 'Right. This is it.'"