How to Master Flat Iron Waves Once and for All

My ideal hairstyle is loose, tousled waves — think "effortless French girl on Instagram." The only problem? My hair is impossibly straight, and even though I'm a beauty editor, and I write about hair regularly, my own styling skills are basic at best. I'm essentially hopeless when it comes to braiding or using a curling iron.

But I finally mastered the undone wavy look a few years ago after TRESemmé global stylist Justine Marjan styled my hair at an event the brand held for editors in New York. Marjan, who counts Ashley Graham, the Kardashians, Olivia Culpo, and Kristen Cavalleri among her clients, gave me the effortless waves of my dreams using a flat iron and a few styling products. Her technique was fast, and seemed easy enough that I'd be able to handle doing it myself.

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Since meeting with Marjan, flat iron waves have become my signature hairstyle. I constantly get compliments on my hair from friends, colleagues, and the barista at my neighborhood cafe. Then, I'm asked how I do it.

While I know how to style my own thick, dry, straight hair, I wanted to get some general insight on how everyone else can do it, too. So, I reached out to Marjan via email to get her tips on curling hair with a flat iron for every hair type and texture.

Step One: Pick the Right Flat Iron

First, Marjan explained why the type of flat iron you use is crucial to achieving this look. Her favorite is the ghd Platinum+ Styler (she's also an ambassador for the brand) because it has round, beveled edges and a built-in temperature control that keeps the iron at a constant temperature so it doesn't damage hair.

"The beveled edges of the iron make it easy to rotate as you work down each section in alternate directions creating an S pattern," she says. "I also use the heated plates of the iron to press down on the hair as I push it through the iron in a wave pattern. This creates a more natural looking wave pattern in the hair that looks less uniform than a curling iron."

Step Two: Prep Hair and Curl It With a Flat Iron

Before getting into it, Marjan suggests prepping hair with a heat protectant product like TRESemmé's Thermal Creations Heat Tamer Spray. Next, she says to separate the hair into one-inch sections and create S-waves by alternating pushing the hair through the iron and pressing the iron down and beveling it as you slide it down the hair.

Step Three: Break Up Waves for a Lived-In Look

Once you've finished your entire head, she uses a small amount of anti-frizz cream like TRESemmé's Between Washes Smooth Renew Anti-Frizz Cream to break up the texture and give the waves a lived-look. She says to finish the look off by spraying TRESemmé Compressed Micro Mist Hair Spray Hold Level 4: Extend all over to hold the waves in place.

When working with curly hair, Marjan recommends blowing-out the hair with a blow dryer and boar bristle round brush, then go in with the flat iron. For this texture, she finishes off the style with TRESemmé Compressed Micro Mist Hair Spray Hold Level 2: Curl, which is specifically formulated to control frizz and keep curls defined.

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This method is easy enough that even I can do it. But I remember, I ended up with dents instead of waves the first time I tried it at home. Marjan tells me that this happen when you press down too hard on the flat iron or hold it too long on one section. "If you don’t keep the iron in motion while gliding through each section, you can create creases and crimps in the hair that are hard to remove," she explains.

Even the simplest hairstyles have a learning curve, but along with these tips, the key is not to overthink it when you're going in with the flat iron. After all, these waves are supposed to look effortless.

The Best Products for Curling Hair With a Flat Iron

ghd Platinum+ Styler

A flat iron with beveled edges is key for creating waves that don't have any creases or dents. This tool also has built-in heat technology so the iron maintains the same temperature throughout your styling session.

To buy: $249; nordstrom.com.

TRESemmé Thermal Creations Heat Tamer Spray

The lightweight spray prevents heat damage and helps hair hold its shape.

To buy: $6; ulta.com.

TRESemmé Between Washes Smooth Renew Anti-Frizz Cream

This smoothing cream breaks up waves for a lived-in, effortless look and gets rid of frizz without weighing hair down.

To buy: $6; ulta.com.

TRESemmé Compressed Micro Mist Hair Spray Hold Level 4: Extend

Finish things off by misting your waves with hairspray. Even though this can is powerful enough to lock styles in place, it doesn't leave hair crunchy or sticky.

To buy: $7; ulta.com.

TRESemmé Compressed Micro Mist Hair Spray Hold Level 2: Curl

Specifically formulated for curly hair, this finishing spray cuts frizz without compromising your curl pattern.

To buy: $7; ulta.com.