Stella McCartney is "careful" when she works with celebrities.
The 44-year-old fashion designer - who can count on Kate Hudson, Reese Witherspoon and Rihanna as fans of her clothes - wants to make "women feel comfortable [and] sensual".
She said: "You have to be careful when you work with celebrities, to be open to their needs, responding to colours they feel comfortable in, while being sympathetic to areas they don't feel comfortable with.
"My job is to make women feel comfortable, effortless, happy, sensual. That is critical, whether it be daywear, eveningwear, lingerie, sportswear. When I am working on a red-carpet dress, there is no difference."
Meanwhile, Stella also revealed she thinks the most important part of a red-carpet outfit is taking an "honest approach" when designing the gown.
She added to the Hollywood Reporter magazine: "I think that the most important part of a red-carpet dress is to have an honest approach and take that to the next level. The glamour, aspiration, craftsmanship and statement should be the same you make with your daily wardrobe, your cocktail wardrobe or even your gym wardrobe. That to me is being honest to yourself and not trying to pretend to be something that you are not.
"Often times when women wear eveningwear, the dress starts to wear them and it comes across as overly complicated, trying too hard and ultimately the result looks uncomfortable, and I don't think that is the right emotion or message. On these red-carpet occasions, the dress should be more the icing on the cake. It's important to find the right way of translating your personality into eveningwear, and to keep it youthful - just the word eveningwear sounds old. So I try to really capture a sense of youth and innocence, simplicity."