I couldn't love being a novelist more. I'm a New York Times bestselling author of mysteries and thrillers (nineteen in all) and I even gave Cosmo an exclusive look at my most recent book, I Came Back for You, which was released yesterday. I love that I get to be my own boss, work from anywhere I want (including my home in Uruguay during the winter), and hang with other incredible authors—people who don't think you're weird because you watch an awful lot of documentaries about Ted Bundy. But even so, nothing compares to the fourteen years I spent as the editor-in-chief of Cosmopolitan from 1998 to 2012.

Every day as an editor felt like an adventure packed with wonderful, wild surprises. This was before remote work was easy—or common—though even if it had been, I wouldn't have wanted it. The office was just too much fun! My staff was made up of extraordinary people who always thought wildly out of the box and helped create an editorial platform that was deeply rewarding.

Sometimes even celebrities joined the fun. Once, for instance, Pharrell Williams dropped by with a singer he was working with so she could perform a song he'd written using Cosmo cover lines. And he brought drinks for everyone!

For me, those years weren't just about overseeing the brand. Cosmo has always stood for something bigger: a place for young women, built on the belief they deserve to live life fully and on their own terms. During my tenure, our readers gave me back as much as they got, and I learned an enormous amount from my team and my audience alike.

Here are six of the lessons I learned then and still rely on today.

Best Fashion Lesson: Pay More

I was always inspired by watching my talented fashion editors at Cosmopolitan (one of them, Rebecca Hessel Cohen, is the founder and creative director of LoveShackFancy). They knew what shapes worked best on them and how a pair of killer shoes could make the whole outfit.

But my favorite fashion trick I learned at Cosmo came courtesy of a perk that went with the job. Those were the peak years of print magazines, and like many female editors-in-chief, I received a generous clothing allowance as well as huge discounts from major fashion designers and Saks Fifth Avenue. As a result, my work wardrobe was stocked with clothes from Prada, Burberry, Max Mara, Michael Kors, Dolce & Gabbana, and Hugo Boss.

Fast-forward more than a decade. Many of these pieces are still hanging in my closet, still in great shape, and—miraculously—still in style. Meanwhile, plenty of cheaper "great deals" I've bought since then didn't survive more than a season, or even a few dry cleanings. The takeaway for me couldn't be clearer: Buy less and pay more for quality. I'm not suggesting you run out and buy a two-thousand-dollar high-fashion blouse. But if you buy the best you can afford, you'll likely wear it longer, look better in it, and save yourself from repeatedly muttering, "Why did I buy this?" in front of your closet.

Best Beauty Lesson: Exfoliate Twice

I was lucky enough to work with two truly great beauty directors during my years at Cosmopolitan, and I spent a lot of time shamelessly pumping them for advice (and/or asking for their keys to the beauty closet). One month, the last director I worked with—the brilliant Leah Wyar, now president of the entertainment and beauty & style group at People Inc.—turned in copy that included a tip she called "double exfoliation."

Double exfoliation? As in… twice?

Leah believed that keeping your skin healthy wasn't just about staying out of the sun or using retinol; It also meant exfoliating in two deliberate steps. First, some type of facial scrub. Then immediately after, a chemical one: something with salicylic or glycolic acid, or even a fruit enzyme. This might be too much for some skin types, fair warning, but for me personally, it was a revelation. I've used this approach every week since then, and I swear it works.

Best Love Lesson: Create Some Mystery

Of all the experts I encountered on the job, few fascinated me more than the late Dr. Helen Fisher, a Rutgers University anthropology professor and the author of Why We Love: The Nature and Chemistry of Romantic Love. She studied love as a scientist and we not only quoted her often, but I once had her come into the office to give a talk to my staff, which left them completely mesmerized.

One of Dr. Fisher's favorite points was that humans are hardwired to respond well to mystery. As much as we may want our romantic partner to be our best friend, she believed attraction is far more likely to endure when each person remains just a tiny bit unknowable (in a healthy, intriguing way).

She also strongly advocated for injecting novelty into relationships (and not just in the bedroom). For instance, take turns planning mystery dates. Novelty, she explained, triggers dopamine, the same chemical that floods your brain during the infatuation stage. In other words, your brain gets tricked into thinking you've just fallen in love all over again.

And here's the best part, in my eyes: It really, really works.

Best Sex Lesson: Tell The Truth

Back when I ran the magazine, we interviewed thousands of people about love and sex, and here's the main thing that struck me: Most people we interviewed were eager, sometimes even borderline desperate, to please their partner both in bed and out. The problem was, they weren't always sure how. So be the boss of your own orgasms and let your partner know—even though it might be a little awkward—what works for you.

Best Career Lesson: Have a Mantra

When I started at Cosmo, the magazine had just rolled out a print ad campaign meant to entice new advertisers and remind old ones who we were. The ads were mostly photographs along with the word Cosmopolitan and one knockout tagline: “Fun Fearless Female.”

I loved that campaign because it captured both the magazine and the women who read it (and still does—Cosmo these days is absolutely fabulous). But before long, I realized it was also a great work asset for me. I held those three words up to every image, article, title, and cover line we were planning to use to make sure they fit the mission. Sure, I knew the brand had to be bold, but having this mantra saved me whenever an editor on my staff was pushing hard for something overly earnest or my inner Catholic school girl reared her head.

I've used that strategy in my work and career ever since. It's great to have a three-word mantra you can keep in mind at all times, guaranteeing you don’t stray from your mission.

Best Life Lesson: Don’t Believe Everything You Think

Those five words above were written as a subhead in a self-help article we ran midway through my time at Cosmo. I can still picture myself top-editing the piece, pausing mid-page, and thinking: “Whoa—this is all about me!” Sometimes, I’d get so caught up in what I was doing that I completely missed other ways to look at a situation, ways that might be better, smarter, and even bolder.

From that moment on, I made a habit of regularly challenging my own thinking. I'd step back and ask: "Why do I believe that?" "Is there another way to see this?" "Could what I'm doing be better, bigger, bolder, more badass?"

This lesson is especially valuable if you're the type who hears advice and immediately thinks, "Yeah, but…" That's something I've done more than I like to admit, and so have some of the people who’ve come to me for advice. A few years ago, when I heard myself say, "Yeah, but…" to my literary agent, I paused, reconsidered what she'd just told me, and ended up following her word. My most recent psychological thriller, I Came Back for You, wouldn't have been nearly as compelling without this.