Sara Donaldson's Brow Expert Shares Her Tips for Perfect Arches

When it comes to beauty, few things are as confusing-or fraught with danger-than grooming your brows. If you decide to see a pro, you'll need to factor in the likely divide in your individual understandings of what you're after. ("Natural and full" can mean two different things to two different people.) And if you're into DIY, there's a whole lot to know before you ever even pick up a pair of tweezers. Even the removal of a single hair in the wrong place can throw off symmetry and ruin your plans for Olivia-esque arches.

We called upon our office brow artist Lien Davies to break down the science of brow shaping, and our current (and forever) beauty crush Sara Donaldson of Harper and Harley to act as a model. Ahead, Davies explains exactly how to recognize any unique brow problems you may have, and how to correct it for yourВ ultimate brow shape.

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Step 1: Prepare

Before you do anything else, take a moment to ensure you have all the tools you need. (More on that below.) You'll also want to set up shop in a space with adequate natural light. Finally, it pays to ensure your environment is calm and distraction-free. Chances are you're not going to get a great result if you're late for work, or simultaneously trying to watch TV. (#TheOA.)

According to Davies, you'll need the following tools to shape your brows; tweezers, brow scissors, a pacer or pencil, a clean popsicle stick, and a ruler. Styling-wise, she recommends a cool-toned brow powder or brow pencil and a Taklon flat paintbrush.

Step 2: Measure

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According to Davies, this step is all about establishing symmetry, consistency, and precision. Davies uses her own unique measuring system, called the Brow Quad Ratio, and styling tool (the Brow Mate-more on this below), to ensure a consistent result every time. The good news? Once you decipher your own individual brow shape, you'll always be able to figure out where your brows should start, arch, and end.В

To start, take a ruler and hold it vertically against your nose so that it sits close to the center of your nostril and intersects with your brow line. Mark this spot with a line relative to your brow thickness. Brows look best with a square-ish front, so try to etch in a suitably full marker without going OTT. Next, position the ruler vertically so that it sits at, or close to, the outer edge of the iris. The spot where it crosses your brow line is ideally where your arch should be. To complete this step, angle the ruler from the edge of your nostril to the outer corner of your eye. Where the ruler meets your brow is where your brow should end. According to Davies, this point is particularly crucial as finding your individual sweet spot will stop your brows from looking over-extended.

Step 3: Outline

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If you're serious about achieving your ultimate brow shape at home, Davies' Brow Mate tool can easily be recreated by using a ruler and brow powder to create a guide on your skin. The following measurements are ideal, but vary from person to person; thickness at the beginning of the brow = 0.8cm, arch length = 3.2cm, tail length = 2cm, overall length = 4.8cm, gap between brows = 2.2cm.В Consider etching this ratio onto the popsicle stick with a pacer for easy measuring each morning.

Davies' signature ultimate brow shape is "a soft, angular arch with an elegant tail length". This classic shape can also be tweaked with unique variations to suit all faces. How do you ask? Round faces look slimmer when brows are styled to look slightly more angular, and angular faces (unsurprisingly) look less so with slightly rounded brows. If you've got a heart-shaped face, go for a softer arch-it'll create a balance between your cheekbones and chin.

Use your Taklon flat brush and a dark brow powder toВ outline your brow shape. Davies suggests using a clear ruler for precision.В OnceВ you've got your outline in place, you'll be able to see more clearly where you need to correct your brows. Any plucking or trimming you do (more on that below) will happen outside of this guideline. (Think of it as a safety net to stop you going OTT.)

Step 4: Trim

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Davies says that whilst trimming isn't compulsory or even necessary for everyone, when done properly it can help fake thickness. To DIY, comb through your brows to check for unruly hairs. Then brush the first half of your arch (from the front of your brow to the arch point) upwards, and lightly trim whatever falls outside the guideline. Next, brush the tail length of the brow downwards and do the same. Always trim in the direction of hair growth.

If you already have neat brows or have a coarser hair type (which can appear spiky when trimmed), resist the urge to snip and use a clear setting agent like Glossier Boy Brow ($16) instead for a similarly sleek look.

Step 5: Tweeze

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Start by tweezing the stray hairs between your brows. Next,В tweeze near or at your top brow line by brushing your hairsВ downward to reveal any stray hairs. Hold your skin taut with oneВ hand, rest the tip of the tweezers against your skin with your other hand,В and remove any hairs you find at the root. To finish,В groomВ your lower brow line by brushing your hairsВ upward and tweezing as above. Make sure to step back after every few hairs and assess your work to prevent over-tweezing. Less is invariably more.

Step 6: Fill In

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This is where the magic happens! Filling in your brows can correct a myriad of problems, including bald patchesВ and uneven arches. To start with, choose a cool-toned powder that matches your natural brow color for an undetectable effect. (According to Davies, warm-toned products look unnatural on everyone.)В

Lightly mist your Taklon brush with water and dip it in your powder, then carefully etch in hair strokes where you need them. Brush the product through as you go to blend it in with your natural brow hairs. You can also do this using a brow putty or pencil but you may need to go over your handiwork with your Taklon brush to lessen the intensity. When you're done filling in, use a small brush and a skin-matchingВ concealer (like Laura Mercier's Secret Camouflage, $35) to trace around your brows. This proВ technique both erases any botched styling and makes your arches pop. Finish off with a swipe of clear brow gel for maximum neatness. Davies loves Maybelline's Brow DramaВ Sculpting Brow MascaraВ ($8) and Benefit's Ready, Set, Brow!В ($24).