Speaking to Harper's Bazaar for the December 2018/January 2019 cover, Robbie said that she would start each day on set getting her head wrapped before a bald cap and wig were put on.
The actress also wore white powder and the shape of her eyebrows was altered.
"Surprisingly, the quick part was the white makeup," Robbie told Harper's Bazaar. "And the heavily drawn-on blush, eyebrows, lips."
In the film, Queen Elizabeth I had scars as a result of smallpox. In order to achieve a similar effect, Robbie wore fake scars that were created using prosthetics.
"With smallpox, you are left with a very badly scarred face, and your hair falling out, so I used that route to try and change Margot Robbie's features, by placing the boils of the smallpox along her bottom lip," Jenny Shircore, the movie's hair and makeup designer," told Deadline.
"It would mean that there were scars left there, which she'd need to cover, which would mean she wore a thick white makeup, blocking out that wonderful bottom lip of Margot Robbie's," she added.
Shircore used the same strategy for Robbie's eyebrows, by "placing the blisters and the boils along the areas that I wanted to eventually cover with makeup, thereby changing Margot Robbie's face, and getting her to the iconic look."