Hi, my name is Hillary, and I’m a pack-a-holic. Some of you won’t understand this addiction, especially those who think packing means “just throw your shit in a carry-on and hit the road.” My trips, you see, often hover around the six-day mark—the magic number that screws up all good intentions. Just short enough that I think I should be able to fit all items into a carry-on bag; just long enough that I know I won’t be able to.

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Let me explain: I’m going to New York for six days. This will include time spent moving my son into his apartment (read: schlepping, hauling, cleaning), so I’ll need a pair of  jeans, tennis shoes, and tee shirts. The trip will also involve a couple of business lunches, which require a really nice pant/sweater/jacket combo, comfortable heels or boots, and a handbag. Did I mention I’m also meeting friends for drinks and dinner at the Carlyle? In goes the dress or blingy top and skirt, some extra jewelry, a pair of heels, nighttime makeup, and the flat iron. Next come necessities like pajamas, undergarments, toiletries, and laptop.

And finally, I add the most dangerous category—the one I like to refer to as the “Just In Casers”—an extra couple of white tee shirts just in case I spill food or get sweaty. My favorite, comfy wedge boots just in case I get blisters from the high heels. Three different belts just in case I want to switch from gold to silver.  You get the idea.

So I end up in big, heavy suitcase territory, which is a deal breaker (and backbreaker) in this age of lost baggage and herniated discs.  

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One Month in Europe. One Carry-On. Could It Be Done? 

This summer, however, my 18-year-old daughter was heading to Europe for a month, and I had an epiphany. Her itinerary was going to include constant city-to-city travel, a slew of hostels and hotels, and daily sightseeing: it soon became clear that a carry-on bag was the only way to go. (Insert teenager screaming.)

That’s when I called in the big guns: my friend, international travel expert, Rick Steves, whose life partner, Trish Feaster, is a packing genius. Trish, you see, works as a tour guide and researcher for Rick Steves’ Europe, spending six to eight weeks on the road at a time, in conditions that don’t lend themselves to my style of hoarding. “It can be a whirlwind—blitzing the continent and never really unpacking,” explains Trish. “Many European historic or boutique hotels simply don’t have elevators, so it’s essential that I can turn on a dime and stay lightweight and portable.”

But here’s the clincher: Trish isn’t one of those no-nonsense, Eddie Bauer-types whose idea of a nice outfit is cargo pants and clean underwear. Trish is a girly-girl who loves her bling, her makeup, her accessories, and lots of outfit choices—all of which she mysteriously fits into one perfect little Rick Steves ”Roll Aboard” bag, and a Tumi tote. Watching her unpack everything is not unlike seeing 40 clowns climb out of a mini car.

Travel Packing Tips: Ahead of the Pack

And finally, I add the most dangerous category—the one I like to refer to as the “Just In Casers.”

In a generous act of philanthropy, Trish gave my daughter and her travel companion a three-hour tutorial, and despite protestations and pessimism, the girls successfully pulled off a carry-on-only maneuver that got them through Europe in style and comfort. Sure, they had to pare down a bit, but more than anything, they learned an important lesson: If you pack correctly, you can fit an entire wardrobe in a breadbox.

Even more generously, Trish is sharing some of her favorite go-to tricks here. (I tried them. They work.)

Roll With It

Rather than filling your suitcase with bulky folded items, roll everything teeny tiny and stuff it (literally) into light-as-air nylon packing cubes: Eagle Creek’s Spector line is a favorite. They can be smartly arranged, Tetris-style, in any suitcase, have expandable zip sides, and one measly 3 x 14 x 10 bag will actually hold upwards of seven shirts. You have to see it to believe it.

Do The Math

Seven tops times five bottoms equals, at a minimum, 35 different outfit combinations—even more if you layer creatively. Stick with a few base colors, like black, grey, and navy, and choose things that go with all three options. Then, add two or three lightweight scarves for a pop of color and extra warmth. They can also be used as a pareo at the beach, a picnic blanket, or a shoulder/head covering when you visit a place of faith.

Next, bust out your geometry skills and start thinking about spatial relationships.

Stuff your sneakers with deodorant, belts, even jewelry. Take advantage of every nook and cranny.  

Weigh In

Add two or three lightweight scarves for a pop of color and extra warmth.

Every ounce counts. Whether it’s jeans, a sweater, or a container to hold cosmetics, always choose the lightest-weight option. Trish actually uses a kitchen scale to weigh every single thing she packs. “It’s always surprising when you learn that your yoga pants weigh more than your jeans.”

Follow the Rule of Threes

If you aren’t going to use something at least three times on a journey of ten days or more, leave it at home. The only caveat: a special-occasion outfit for a destination wedding, formal event, or cruise-ship dress code.

Test-Run Your Shampoo

Wondering how much lather you really need for your ten-day vacay? Here’s how to know: Ten days before your trip, fill up a two- or three-ounce travel bottle with product, then use it exclusively at home. If you don’t make a dent, try bringing a smaller bottle on your trip. If you find you need more—highly unlikely, says Trish—consider bringing an extra one-ounce bottle to supplement. Go through this regimen with all your toiletries, and chances are, you’ll be paring way down.

An Iron-Clad Tip

If you’re wedded to heat-styling appliances, bring just one and make it a flat iron with a one-inch barrel. You can use it for straightening, for curling, and, in a pinch, for ironing your clothes.

The Trial

So I tried it. A week-long trip in one carry-on suitcase. Yes, I am both boasting and glowing with pride. My itinerary consisted of a relaxed weekend at a country house, followed by four action-packed days in Manhattan. The latter included one Broadway show, three dinner dates, two coffees—and while there was no partridge, the country house did, indeed, have a pear tree.

Watching her unpack everything is not unlike seeing 40 clowns climb out of a mini car.

I used a packing cube and stuffed that sucker to the gills. Shoes were the biggest problem (even Trish acknowledges this is where she bends the rules a bit), seeing as I “needed” heels, tennis shoes, walking shoes, and flip flops. And though I wanted to bring boots—I briefly considered wearing them on the plane for six hours—they ended up in the no-go column. Nevertheless, that little suitcase was freaking heavy, and I will admit to accepting an assist from a tall, brawny man when I went to hoist it into the overhead compartment.

Believe it or not, I didn’t wear everything I brought, but that doesn’t mean I’m going to lighten up even more on my next trip. I can’t quite shake the “umbrella” thinking: You’ll only need it if you leave it home.      

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A version of this article was originally published in December 2017.