Sienna Miller Boarded the Eurostar in the Chic Outfit I Always Wear to Travel

Years in fashion have taught me that mastering the art of travel dressing is no small feat.
Whilst comfort is always a priority in my day-to-day wardrobe, it becomes even more crucial when navigating the high step count and many hours of waiting around that are tediously synonymous with a day of travel. At the same time, there’s something to be said for arriving at your destination looking put-together, especially if you plan to hit the ground running. That’s why I swear by a few tried-and-tested travel essentials whenever I'm going abroad.
Clearly, Sienna Miller has reached the same conclusion. A seasoned traveller herself, the actor was recently spotted breezing through King's Cross St Pancras, suitcase in tow, in an effortlessly chic spring ensemble that demonstrated the very formula I rely on for travel days. Returning from a busy week in Paris, Miller disembarked the Eurostar in London wearing the single shoe trend I consider a must-have for anyone who travels frequently: ballet flats.
Elegant yet practical, this staple is comfortable enough for long stretches on your feet and, crucially, is easy to slip on and off for security checks. Miller chose a pair of Gucci Horsebit Ballet Flats, landing on one of the season's favourite shoe trends whilst ensuring lasting comfort. She styled them with denim, choosing a relaxed, frayed-hem pair that gave her look a casual yet considered energy. Layering on Chloé's Double-Breasted Wool-Blend Tweed Coat (£1614), Miller's layer provided just the right amount of warmth for unpredictable early-spring temperatures.
Whilst Eurostar security is much less of a faff than air travel, I still stand by the importance of a fuss-free shoe. Whether I'm heading through a security checkpoint or simply want to slip into something more comfortable mid-journey, a polished yet easy-on, easy-off shoe is always top of my packing list.
And then, of course, there's the debate around jeans. Whilst some might shy away from denim on travel days, deeming it too restrictive, I’d argue that the right pair—relaxed, wide-leg and well-worn—can be just as comfortable as any leggings or joggers. The added bonus? They instantly make an outfit feel more put-together, ensuring you arrive at your destination looking just as polished as when you set off.
As someone who has spent years fine-tuning her own in-transit wardrobe, I can confidently say that this is a look worth bookmarking for your next trip. Read on to discover how to copy the outfit below.
SHOP SIENNA MILLER'S TRAVEL LOOK:
SHOP JEANS AND BALLET FLATS:
I always come back to Agolde for its chic and wearable denim collection.
These mid-wash jeans are so easy to slip into a capsule wardrobe.
Style with a white tee or wear with a billowy boho blouse.

Natalie Munro is Who What Wear UK’s news writer and has worked in the fashion industry since she graduated with a degree in Journalism from the University of the Arts London. Natalie’s experience in the industry spans journalistic and styling roles that have seen her work for publications including British Vogue, Conde Nast Traveller, Vogue Ukraine, AnOther Magazine and Elle UK.
With an interest in uncovering the latest fashion trends, Natalie takes a leading role in identifying news for Who What Wear UK. Reporting on a daily basis, Natalie focuses on trends on and off the runway, as well as street style and celebrity fashion. Natalie also creates content for Who What Wear’s social channels including TikTok and Instagram on a weekly basis.
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