Pat McGrath second from the left, with models Karen Elson, Adwoa Aboah, and actor Sophie Flicker at a gathering in New York.

Pat McGrath second from the left, with models Karen Elson, Adwoa Aboah, and actor Sophie Flicker at a gathering in New York. Photograph: Taylor Hill/FilmMagic

Skin is unpredictable. A lot of the models I work with have done so many shows, going through extreme weather. The makeup I use has been developed to sustain all different temperatures, including everything that goes on backstage, or on location in 100 degree heat.

The world’s obsession with beauty makes my job more exciting because everyone wants to talk about it all the time, even when they don’t work in the industry. I’ve seen so much change in skincare over the years – I’ve spoken before about my mother using cocoa powder on her face because she couldn’t find powder in the right shade. Now, more brands are producing makeup for a wide range of skin tones; my own foundation comes in 36 colours.

People are also really clued up now, not just getting tips from their mothers, as I did, but snatching them from online. Kids can write beauty books by the time they’re eight. It’s exciting.

The more obsessed you are with makeup, the more you look at your skin. Theatrical contouring [as seen on the Kardashians] has become popular, but real contouring is about bringing light to the higher planes of your face, the cupid’s bow, centre of your nose, corner of your eyes and eyelids. The contour colour – the darker shade – should be so close to your skin tone that no one can see you’re wearing it.

People want a seamless finish with foundation. When I was doing my makeup “system” at shows 25 years ago, I’d put Skin Fetish [McGrath’s highlighter] on my models, and journalists would come in and say, “What is that?” and I would be hiding it. I knew one day it would be part of my own makeup range and now is the right time. It’s so, so gorgeous to have that “lit from within” look.

The new generation are all about layering products on thickly, but it’s important to look after the skin underneath. I use Augustinus Bader products and go to a dermatologist. People say they’re expensive, but they don’t cost as much as a pair of sneakers or a laptop. It’s important to invest in your skin.

Pat McGrath, 2019
 Pat McGrath, 2019 Photograph: PR Photo

I’d love to be able to turn back time with skincare. I’ve always said, “Give me a pill that could knock off the last 15 years, that would be great.” Having good skin means you feel better about yourself. I believe in drinking a lot of water, exercise, lots of sleep, a healthy diet, cutting out sugar. Whenever I do these things, people say, “Look at your skin!” and I’m like, “Yes, now pass me that cake.”

Falling asleep in your makeup is definitely bad for your skin, but we all do it, don’t we? There are a lot of people who go to bed in full makeup because they’re scared for their partner to see them without it – that’s major. I’m into a good reveal myself.

I’m inspired by everything I see, everywhere I go. There are no no-nos – sometimes something technically “wrong” can inspire something that’s right. I remember back in the day when everyone was wearing beiges and browns – that look from the 80s and 90s – I saw a woman, who must have been 80, walking into a department store in London with acid orange lipstick on. She looked beautiful. I remember thinking, right, I’m doing that on my next editorial.

Perfect skin in 2019 is skin that looks perfected but real. It’s subtly enhanced. People want to be able to do their makeup in 10 minutes without looking like they’ve fallen into a tank of flour. But mostly we want to look like ourselves.