Martha Stewart's Makeup Pro Reveals the $16 Buy Behind the Icon's 'Sports Illustrated Swimsuit' Glow (Exclusive)

Martha Stewart sent the Internet ablaze on Monday when she revealed she's one of four stars posting on the cover of Sports Illustrated Swimsuit's 2023 issue (others include Megan Fox, Kim Petras and Brooks Nader).

In her exclusive interview for the magazine launch, Stewart, 81, told PEOPLE what the experience meant to her. "It's important to stand up to challenges, whether they're beauty challenges or intellectual challenges, even philanthropic challenges," she shared. "To be able to stand up and do it — to me — is so fun! And this is accomplishing something that not everybody would accomplish."

To get ready, Stewart upped her fitness game and modified what she ate.

"I didn't starve myself, but I didn't eat any bread or pasta for a couple of months," Stewart told Savannah Guthrie and Hoda Kotb on the Today show. "I went to Pilates every other day and that was great; I'm still going to Pilates every other day 'cause it's so great. And I just, I live a clean life anyway — good diet and good exercise and healthy skincare and all of that stuff."

Stewart's dedication to her detailed skincare routine provided a luminous canvas for her longtime makeup artist Daisy Toye. "Her skin is everything. She has the most amazing complexion," Toye says. Here, the beauty pro shares exactly what she used to make Stewart look bronzed and glowy for her big cover moment — and what's it like to work with the icon.

PEOPLE: How long have you and Martha been working together?

Toye: "Fifteen years! I used to do makeup for her magazine and one time the editor called me and was like, 'Martha needs a makeup artist!' and I was like, 'Wait, Martha, Martha?!' I was a wreck. Then she started booking me every day. I'm literally with her five days a week. Sometimes more. I see her more than I see my mother."

PEOPLE: What's Martha's usual makeup vibe?

Toye: "When I first started working with her, she knew what she wanted and she was very involved with what I used. But she has evolved over the years. Now she trusts me. But it also depends on what mood she's in. I kind of feel her out. I really like to glam her out. Because then she feels so good. She takes all those sexy selfies."

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PEOPLE: Martha's Instagram is pretty amazing.

Toye: "I know. It's me taking the pictures. There's a picture of us in Miami when we were just hanging out by the beach. She was like, 'Let's go up and do makeup.' I gave her smoky eyes, nude lips, bronzy skin, and then she started feeling herself. She's like, 'Take a picture!' "

PEOPLE: How involved did she get with the Sports Illustrated shoot?

Toye: "She wanted to look really tan. I'm so happy she got a spray tan because she looks so good with it. The photographer had a very strong direction. He wanted a smoky eye in a lot of the pictures. There was a point during the shoot when she had eyeliner dripping down, because she was in the ocean. He's like, 'Keep it, I like it.' And I was like, 'No, we don't want that look.' She wants to look like herself. She wants to look glamorous, she wants to look pretty."

PEOPLE: She looks gorgeous. What were the key products?

Toye: "L'Oréal Paris True Match Lumi Glotion. I use it every day on her. I go through a tube every week. It's how she gets that dewy look, like she just got a facial. I'm obsessed with it. I also used Natura Bissé Diamond Cocoon Sheer Cream. It's very rich and it has a tint. You don't even need foundation. I also can't live without Chanel Les Beiges Healthy Glow Bronzing Cream. On her body I used L'Oréal Paris Beach Bae Face & Body Liquid Luminizer. It's unbelievable. Everybody on the shoot was going crazy for it."

PEOPLE: What are some of your other go-tos when you do her makeup?

Toye: "She only likes a nude lip. I have received like 3,000 DMs asking for her lip color. It's a mix of things, but my favorites [include] Trinny London Lip Colour Lip Luxe in Eugenie and Bunny."

PEOPLE: What has it been like watching Martha become an "It girl" at 81?

Toye: "Oh my God. I'm so proud. And I do feel somewhat responsible for it, because she's just letting me do my thing. She's definitely loosened up, she's getting sprayed tans now. This was not Martha 10 years ago. She wants to stay looking sexy. She has a great body. Sometimes I can't keep up with her. We were in Vegas a few weeks ago and after dinner and drinks she's like, 'Snoop just texted me. He's DJing at Aria.' She's like, 'Let's go.' "