Shampoo tycoon: 'leave the details to the experts'.

Carolyn Aronson has built It's A 10 into one of the most successful hair care brands in the US.

Now she's launching in Europe. But this hasn't been the first company she's formed. The first one collapsed.

The reason for that, she says, is that when she was designing the products she tried to solve all the technical details herself. Nowadays, she says: 'leave it to the experts'.

Video journalist: Jeremy Howell.