Gray Lady: Use a thin strip of tape to separate the gray from a bright pop of color–just pull it off before the polish dries.

By day, she’s Ms. Park, teaching English to 10th-graders at TechBoston Academy. By night, she’s Elle L. Cool Jam, racing around a roller rink in the Boston Derby Dames league. But it’s online where Nina Park earns the cred she needs to hang all day with teenagers. There, she’s @NinaNailedIt, a nail art pro with more than 20,000 Instagram followers who have come to expect new swoon-worthy designs every week.

Park wakes up as early as 6:30 am on Saturdays to get to work, postponing grading essays in favor of a design routine that might seem Sisyphean if it weren’t so enjoyable. She paints a week’s worth of designs in a matter of hours. One intricate look featuring gold charms and turquoise marbling is painted, photographed and then wiped clean; next up could be a starry galaxy or even digits inspired by a cable-knit sweater. “Then I take them off and paint the final set that I’ll wear for the week. Isn’t that crazy?” she says. “It’s a lot, but I think that painting my nails just kind of helps me relax from the week.”

Art itself isn’t new to the beauty guru; she took art classes growing up, “but nothing ever stuck.” Bored of her go-to black nails, she taught herself nail art with the help of Pinterest and online tutorials. And now she’s teaching others, with a workshop on floral and ombre nails planned for Jan. 22 at the North End’s Savas Studios. “I love giving people tips and then having them come back and be like, ‘Look what I’ve done!’” she says. “I want to see people with more nail art in Boston. I’m just ready for that.”

Peachy Keen: Who says tips should have all the fun? Try a half-moon mani in a ladylike pastel, using a small, thin brush for precise application.

On the Matte: A mattifying top coat adds the finishing touch to this neon-meets-neutral design.

Easy A

Park put together a lesson plan to help you nail a perfect set.

1. Buy cheap nail art brushes from eBay and trim them down to your taste.

2. Practice writing the alphabet with your less-dominant hand to improve dexterity.

3. Use toothpicks, bobby pins or pens to make dots.

4. Utilize Elmer’s Glue around your cuticles to prevent polish from getting on your skin when making gradients.

5. Dip an angled eyebrow brush in pure acetone to clean up any stray polish around the cuticles.

6. Dab coconut oil on the cuticles to give your nail art an even more Instagram-worthy shine. #nofilter

Paint the Town

Park had more than 200 bottles in her arsenal before she became sponsored by Sally Hansen, so it’s safe to say she knows polish like the back of her hand. Here are a few she used to achieve these looks:

Sally Hansen Peach of Cake

Thanks to its versatility, Park has gone through bottles of this hue, which is free of three of the most common toxins found in nail polish. // $8 at CVS

Smith & Cult Stockholm Syndrome

This “five-free” polish can be worn on its own as a sleek neutral or paired with a bright color for a more chic finish. // $18 at Shag

Cult Hermosa Beach

This toxin-free, vegan-friendly polish from California carries a one-coat guarantee. // $10 at cultcosmetics.com

Where to Buy It:

CVS 285 Columbus Ave., Boston (617-236-8538) cvs.com

Shag 840 Summer St., Boston (617-268-2500) shagboston.com