Ann-Sofie Johansson, 47, whose designs end up in 2,000 stores in 37 markets around the world, said she keeps a close eye on bloggers and says the popular television show "Mad Men" has had a big impact on fashion. "
Everyone is talking about Mad Men," she said, referring to the show about a New York ad agency in the 1960s. "It has actually had a great impact on fashion. It's a very feminine look, with lovely dresses."
Johansson -- who is two years into her role at the world's third biggest clothing retailer -- said today's trends are global, noting that H&M's best sellers were top world over rather than in a specific market.
Her designers create fashion for all markets at once rather than tailoring trends for individual countries, though they often test products in key centres before launching globally.
She got her start in fashion working as a sales clerk at one of H&M's retail outlets in the late 1980s and joined the design team when it had a staff of just 10 or 15.
Today, the fashion giant has more than 100 designers from around the world, nearly all of whom are based in Stockholm and work on collections for three seasons at a time.
Johansson's teams pore through magazines and trend books, visit flea markets and vintage fairs and fly to fashion centres London, Paris, New York and Tokyo for inspiration.
She also gets inspiration from the Swedish capital.
"Stockholm is a very trendy city," she said, sitting in a room full of "mood boards", mannequins and art books. "If I want to have some inspiration I can always go down to our restaurant to have lunch. It's like a fashion show every day."
One of today's biggest influences on the everyday shopper, she says, are fashion blogs such as Bryan Boy and Style Bubble.
"A lot of people are following bloggers, reading them, wanting to look like them. If there is a certain garment that a blogger has written about we can instantly see that there is a huge demand for that garment."
The highly secretive company competes in a fierce retail market with the likes of Zara-owner Inditex - the world's biggest clothing retailer - GAP and Esprit. It tends to work with very long lead times, but can test new products in a few cities and smaller shops.
"If we see demand for (a piece) we can repeat it and then make it for everyone and place it in bigger volumes, and that process can go very quickly," she said. A "repeated" product can reach retail floors as quickly as two weeks.
Johansson keeps an eye on competition -- she walks by a Zara store on her way home from work most days -- and a report that breaks down sales figures to individual markets, specific garments and even colour lands on her desk every Monday.
Johansson calls herself a fashion addict. "Right now I like the 70s vibe, the more well-dressed," she said, herself dressed in a green H&M top, khaki slacks and a blazer by Danish designer Marlene Birger.
H&M is set to release this month a special collection with luxury designer Lanvin, following up on successful launches with other guests such as Karl Lagerfeld and Jimmy Choo. "The collection is really colorful and party-like, a lot of dresses," she said.