"When I started the new collection, the only thing I knew I wanted was the sound and feel of Sinead O'Connor," says designer Christopher Shannon, from behind a big white desk overlooking his busy studio in Stoke Newington.

This isn't a sentence you hear every day in the world of fashion, but Shannon, a Central Saint Martins graduate whose designs offer a modern riff on sportswear, has long had a fascination with the Irish singer. "Sinead would have been a super model if her career had launched now," he tells me as we look over his new collection, which will show at London fashion week on 22 February. "Karl [Lagerfeld] would have had her in there with a skinhead."

More on the O'Connor-inspired collection later (of which, sadly, there are no preview pictures). I'm here to find out what makes the designer tick. Given his association with sporting chic, I wonder whether Shannon will be going to the Olympics, but it turns out he didn't apply for tickets. In terms of favoured fashion houses, he says he'd quite fancy working for Moschino - a union I am wholeheartedly in favour of. And when asked about the new Madonna single, Give Me All Ur Luvin', Shannon responds that he preferred it when Nicola Roberts sang it. Shannon is on fire with quick wit and one-liners, but he is also reflective and prone to a few serious moments, especially when talking about Sinead.

The Christopher Shannon show at London Fashion Week Spring/Summer 2012. Photograph: Gareth Cattermole/Getty Images

Meanwhile, his new season moodboard hangs behind us. It comprises a load of photocopies tacked to the wall, among which are images of a girl with a helicopter weave, Snoop Dogg in a jumpsuit and a picture of a vintage sweater with transfer stickers all over it. Cool and oblique, it seems a fitting backdrop to our Q&A session. "Whose wardrobe would you 'no thank you' to?" "David Beckham," he responds. "I don't dislike him but he does nothing for me." I ask him about the face paint on his models (he never tries it as he hates to put things on his face) and what makes him roll his eyes ("Impatience. Stupidity. Incompetence.") "What's the worst question a journalist has asked you?" I venture. "Oh, just the fucking boring ones," he whips back grinning.

Shannon didn't enjoy last season. He'd taken on too many things outside his own label, and for autumn/winter 2012 he wanted to refocus. Sinead appears to have helped him do this. Apart from the influential images of O'Connor by John Maybury and Kate Garner, the singer's appeal, he says, is that she made work that was built to last. "I think it's bringing the personal touch to things, having a point of view and following that through which makes good work last," he says. "Fashion is fashion and that should date, but there's something about the work that should last."

The Kidda range. Photograph: Christopher Shannon

Looking back over his previous collections, you can see a witty, sexy and spirited aesthetic evolving, but, crucially, with a carefully refined commercial sensibility. Admittedly, I wasn't always overwhelmed by his earlier shows but this is a label that has matured. The last two collections were particularly strong, and it's brilliant to see a young, independent British menswear label establish such an instantly recognisable and focused-looking handwriting. Shannon's distinctive qualities have also translated to a spin-off label, KIDDA, a much buzzed-about jersey line featuring his signature paisley and chain prints on t-shirts, vests and sweats.

There is also a rail of fresh clothing hanging in polythene bags, samples from his forthcoming a/w 2012 show that we're privvy to a sneaky look at. Inside them: denim look T-shirts made from jersey, a patterned jumpsuit, zippy trousers (think a sleek combat with no sticky out pockets), and a reflective jacket in a Burberry-style oversized check that features a zip-off hood and a custom rib knit bottom. There are patchwork bomber jackets - "we always do a bomber but this season I wanted to do 17!" - and patchwork jeans - "they're like a cross between gardening trousers and Michael Jackson trousers." Plus, there will be "knits with windows" featuring peephole sections, which will reveal a pattern beneath, and a shoe collaboration with Kickers.

"I like it better than last season," he says cheerfully. "The fabrics are better, the fits are better ... In menswear, a few extra centimetres in the wrong place really naffs things up."

Christopher Shannon shows his autumn/winter 2012 collection at London fashion week on Weds 22 February at 11:15am.