“I’ll alter the contrast to make the facial features stand out, using a shade range between pure white and very dark grey,” he continues. “I also make sure that all areas of the photo reference are visible.

“For example, sometimes the contrast on the face is perfect, but the person has dark hair against a dark background and the texture of the hair isn’t really visible. I’ll lasso that particular section of the photo and tweak the contrast of that specific bit.”

For fleshing out a portrait, Finnish artist Minni Havas (pekkafinland.fi/minnihavas/) recommends starting from your faintest colours and carefully adding them from lighter to darker on top of each other.

“That way you can still make corrections to the image while drawing,” she explains. “When I draw or paint skin, I keep in mind that human skin is translucent and covers blue and reddish blood vessels. So the skin isn’t monotone.

Annelie Carlström for the Swedish fashion label Minimarket, which appeared on playing cards given away with their clothing

“I never use black for shadows on skin or textile,” she adds. “Instead I use complementary colours mixed with darker shades of the base hue.”

Cardiff-based illustrator Kath Morgan (kafine-ated.net) uses a technique of working upwards through the levels of detail for both digital painting and acrylic. “What this means is that I’ll start out by blocking in the main areas of light, dark and colour, making sure that all the structures are as I want them,” she explains. “Then I’ll refine these with smaller brushes during the longest part of the painting process.

“The details go in last. Getting caught up in detail too early can result in a distorted image you can’t bear to erase, or boredom when you realise how much work is left to go.”

Vincent, for his part, starts with a white canvas. “I cover it with a couple of layers of transparent colours and half the work is done. A lot of the skin will be made out of the underlying colour. A beautiful trick born out of laziness, but it works.”

Top & Bottom - Personal pieces by Minni Havas

For working on the face, it seems there as many techniques as there are human expressions. “It’s important to get the shape of the face right first,” says Stanley Chow (stanleychow.co.uk). “If you get that wrong, it’s very hard to put the eyes, nose and mouth in the right place in relation with each other.” That partly explains why Stanley’s favourite features in Illustrator, or at least those he uses the most, include the Alignment panel and the Reflect tool.

Peter views the face as the sum of its parts. “They all interconnect,” he says. “A smiling face will affect the light and shade on the cheeks or the lines round the eyes. With this in mind, I tend to build up shade quite slowly in layers, working on lots of areas of the face simultaneously.” He says this helps unify the tones and lets every element blend into the next.

Minni advises that you also spend time on building up textures on across the face and hair. “For example, eyeballs are covered with fluid and mouth is soft but wrinkly,” she says. “Think about the face as a 3D object and draw the strokes according to the shape.”

It’s not necessary – or even possible – to replicate every single detail in a face, and adding too many lines may give a messy look. “I start by reducing details until I get the very essence of the face,” says Oscar. “I try to be tight with the black ink, because I adjust and complete the details of the expression with lights and shadows.”

“A little light in an eye does wonders,” notes Anje Jager, while Peter tries to make the eyes a focal point by always leaving the whites perfectly white. “If you look at a photo of a face, the brow often casts some shadow over the whites of the eyes,” he says. “By keeping them white, though, you can add a little extra impact.”