A Brow Expert Taught Me This Face Mapping Trick—and Now I’ll Never Tweeze Without It

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I remember the first time I saw a photo of Cara Delevingne on Tumblr—specifically her eyebrows. The brows that launched a thousand (more like millions) sales of Glossier’s Boy Brow. Since then, I’ve chased every trend: the full Delevingne arch, the 90s pencil-thin resurgence, and now, finally, the slow work of regrowing what I had all along.

The thing about brows is that they control everything. They shape your expressions, frame your face, and have an outsized effect on how put-together—or not—you look on any given day. Which is why finding the right shape for your specific face matters more than following whatever trend is currently having a moment.

Featured image from our interview with Sami Bernstein Spalter by Michelle Nash.

To figure out how to actually do that, I turned to Amanda Robinson, owner of Iris+West Lash Co in Los Angeles and the person responsible for the brows of Mandy Moore and Molly Baz. With over a decade of experience in the beauty industry, Amanda has built a loyal following in Los Angeles for her highly customized, natural approach to lash extensions and brow design. She founded Iris+West after seeing firsthand the damage and overly uniform results that came from poor application techniques and set out to redefine the space with a focus on lash health, restraint, and personalization.

Her advice was simpler than I expected—and more useful than any brow tutorial I’ve ever watched. Buckle up.

The Face Mapping Technique You Need to Know

Before you tweeze a single hair, Robinson recommends this three-point face mapping method to find your ideal brow shape:

“Those three points give you your ideal start, arch, and end,” Robinson says. Whether you’re getting your brows shaped professionally or filling them in at home, she adds: “Think of the top and bottom lines of your brow like railroad tracks—they should run parallel.”

Work With What You Have

The through-line of Robinson’s philosophy is refreshingly simple: stop fighting your natural brows. “My biggest piece of advice is to work with what you naturally have,” she says. “Some people naturally have more arch, while others have a straighter or more rounded brow. While we can definitely refine the shape, I find people feel their best when we aren’t fighting what’s naturally there too much.”

On the thick-versus-thin debate, Robinson is clear that shape and arch matter more than thickness. “As a general rule, bolder brows tend to suit stronger, more prominent features, while thinner brows complement more delicate ones. Fuller brows also tend to give a more youthful look.” But ultimately: “Whatever makes you feel most confident is what’s going to look best on you.”

Common Brow Mistakes—and How to Fix Them

Even with the best intentions, brows go wrong. Robinson’s most common culprit: “The biggest mistake I see is cutting them too flat and straight across the top.” Her fix? “Trim one hair at a time, brush them in the direction you like, and go slowly—you can always take more off, but you can’t put hair back.”

Other mistakes worth avoiding:

How to Support Brow Growth

If you’re in regrowth mode—whether from over-tweezing or just years of thin-brow trends—Robinson points to peptide-based serums as her go-to recommendation. “Peptides condition and strengthen the hair follicle and promote healthy growth.” One thing to avoid: prostaglandin analogs. While they can stimulate growth, Robinson flags them as worth approaching with caution—check with your dermatologist before adding one to your routine.

For definition, shape, and filling in sparse areas, a pencil is the most precise tool in your brow kit. Robinson recommends using light, hair-like strokes and letting the spoolie do the blending work.

If your brows are naturally full but need taming, or you want that brushed-up, lamination-adjacent look without the commitment, a gel is your move. Clear formulas work on every brow color; tinted ones add a soft fill.

For anyone in regrowth mode—from over-tweezing, thinning, or just years of trend-chasing—a serum works on the follicle level rather than the surface. Consistency is what makes them work; these aren’t instant-gratification products.