Kristen Stewart's Makeup Artist Breaks Down the Unmissable Beauty Moments in Spencer

For Stewart's day-to-day Princess Diana look, Panepinto says she kept it light and fresh. First, there was a lot of prep work before getting to the makeup, starting with the A-list favourite Augustinus Bader The Cream (£205), which she used to create a radiant base. Then, to create Princess Diana's rosy glow, she used the lightweight Glossier Skin Perfecting Tint (£29) followed by the Benefit Benetint Rose Lip & Cheek Tint (£15.50), a sheer pink blush. Because the eyes were such an emphasis for the late royal, she amped it up just a notch with the Chanel Le Volume Mascara (£30) and a brown eyeliner from Marc Jacobs to create a soft, romantic look.

"Having worked with Kristen for years, I'm fortunate that I know her face well and I know the products that work for her," Panepinto told POPSUGAR. "For this look overall we wanted to keep it simple and true to a lot of the images you see of Diana in real life. We didn't want to try and copy from anything complete, but instead to create an image that felt timeless. Sometimes we might use a lip colour that was similar to images we looked at to pay homage to a real reference point."

Princess Diana rarely changed her hair, preferring to stick with the styles that she knew and loved. It's an essential part of the "Diana look", and the team understood that nailing this part was key. To get the styles, Stewart wore wigs all throughout the film to re-create Princess Diana's iconic hairstyles, including the shaggy cut that's synonymous with some of Diana's biggest fashion moments in the 1980s. These were handmade by Samuel James and styled by the film's makeup and hair designer, Wakana Yoshihara.

Because Princess Diana was so high-profile and photographed so often, Panepinto told POPSUGAR that sourcing inspiration images and reference material was easy. Some of her most important moments were captured on film all throughout her life, including her wedding to Prince Charles.

Panepinto even managed to find inspiration for the movie much closer to home: "My mum actually had some books from the '80s and '90s that I found images of Diana in," she said. "I also watched documentaries about Princess Diana and filled in any gaps by hunting down images online."

She says that her favourite outfit in the film was Diana's intricate Chanel gown, which was painstakingly re-created for the movie's poster. Later in life, after her marriage ended, Princess Diana no longer wore the brand. She said that the CC logo reminded her of her ex-husband, Charles, and his rumoured mistress, Camilla, who apparently gifted Charles with a pair of CC logo cufflinks as a gift when he and Diana were married.