Peter will also often work by turning both his sketch and the original reference sideways or upside down. “This can work by helping the logical side of your brain to forget you’re drawing ‘an eye’ or ‘a nose’,” he says. “If you can start to view the portrait as an abstraction of light and shade, it will be more truthful.”

Helsinki-based Miika Saksi (miikasaksi.com) has some unconventional advice for creating the best portraits. “Lie,” he says. “If you are doing a portrait of a person who doesn’t look interesting or working from a photo that has imperfections, you don’t have to be compliant with the original image. You can make eyes bigger and brighter, the chin stronger, teeth whiter and cleaner, features symmetrical, and so on.

“Make the person look interesting and awesome, because you can. It doesn’t have to be so truthful. It’s your vision.”

Schin disagrees, preferring to try to find perfection in imperfection. “A face that is too beautiful and perfect can be ugly or just plain weird,” she says. “Nobody’s face is perfectly symmetrical.

Above (top to bottom) Nina Simone, Gwyneth Paltrow as Margot Tenenbaum, and Bill Murray, all by Stanley Ch

“First I try to make the face as beautiful as I can, then sometimes I purposely make it cockeyed or the eyes slightly asymmetrical. As long as the face looks right, I don’t really worry too much about being 100 per cent anatomically accurate.”

Scarlett Johannsen (top) and Irina Lazreanu (bottom) by Anje Jager