German supermodel Heidi Klum is shocked by her catwalk success, because she couldn't even smile for the camera when she started out.

The 32-year-old struggled with her femininity during her early fashion years, and credits her modelling agency with refining her beauty.

She says, "I had to learn everything - especially how to smile.

"In the past I had a very artificial smile. When I came to my agency the first time, they cut my finger nails, because they were like shovels. I wore baggy pants and big bomber jackets.

"I had to learn how to dress figure-hugging and feminine. Jeans, large sweaters and sneakers are just not the look for a top model."