A few weeks ago we crowned Elle Fanning the “fashion princess” of the Cannes Film Festival because she wore one show-stopping couture creation after another (you need to catch up on them all here). And ever since her fashion fairy tale moment, she’s been continuing her press tour for her new film, The Beguiled, in more head-turning fashions. Monday night we caught up with the star at the L.A. premiere to get all the fashion details.

At the premiere, Fanning wore a chrome sequin Naeem Khan gown, which featured a mature bustier-style top with elegant ruffle straps and a full dramatic skirt, plus over $150,000 worth of Tiffany & Co. diamond jewelry and Tamara Mellon heels.

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“This dress I actually tried on today, I wasn’t sure what I was going to wear to this, so this was a last-minute try on, but I love it,” Fanning told PEOPLE on the red carpet. “It has a little corset feel, and it doesn’t hit the floor, so it’s easy and summery.”

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That kind of intuitive thinking is how she approaches many of her other fashion decisions too. “I try to change it up and go on my gut feeling,” she says about her sense of style. “It’s very instinctual, and I do know what I like. I am very particular with certain things, and I’ve always just wanted to experiment and have fun with my clothes, so that is it. I’ve always been, like, ‘be true to yourself’, and it sounds cliché but that is how I do it.”

While her corset moment on Monday night looked distinctively up-to-date thank to that shimmery metallic finish, her corsets in the film were very authentic to the Civil War time period thanks to director Sofia Coppola’s close attention to details.

“Sofia [Coppola] did such an amazing job during rehearsals — I really didn’t know so much about the women of that time and what they did, what they felt, but we had sewing lessons, bible study, a Civil War re-enactor that came to see us and taught Nicole [Kidman] to bandage up Colin [Farrell] in the right way, so there were so many different things because Sofia wanted to be very period specific,” Fanning shared.

If you’re wondering if Fanning did any of her own costume work on set, she’s not setting her sights on design any time soon. “Sewing I’m not really good at,” she confessed. “But we were all there together, so I think that the main point of it was that we all bond in a way. I’m not great, I’m not joking.”

What do you think of Fanning’s premiere dress?

–reporting by Reagan Alexander