Tawny Sorensen usually keeps quiet on set. As a double for Margot Robbie, Carrie Coon and other stars, her job is to stand in for them while they go on a break, so the crew can set up lights and cameras.

That changed on “Russian Doll.” For the hit Netflix series, the normally reserved blonde had to embody the notoriously larger-than-life, fast-talking, big-haired Natasha Lyonne — the show’s creator and star, who encouraged Sorensen not to hold back.

“We were pre-rehearsing this scene where Natasha’s character falls down the stairs, and there were so many expletives,” says Sorensen, who donned replicas of Lyonne’s fiery red wigs and sharp-shouldered jackets during the entire shoot. “I was yelling at everyone and dropping F-bombs, and the boom mike operator was so thrown off guard, like, ‘Tawny! I didn’t know you had that voice in you.’ ”

Sorensen, 37, has worked as a stand-in, while acting and directing and writing her own projects, for a decade. She’s even worked with Lyonne before, as her double for “Orange Is the New Black.” She tends to avoid actors on set, so as not to disrupt their process, and so she was shocked when Lyonne asked her to audition as her stand-in for “Russian Doll,” about a woman who keeps dying and reliving her 37th birthday over and over again.

“I walked into the interview and [director] Leslye Headland was like, ‘I’ve heard so much about you,’ ” the Upper East Sider recalls. “And because I don’t talk on set, I was, like, ‘What did Natasha tell you about me?’ ”

Sorensen, who grew up in Lynbrook, LI, began performing at age 3, when she had her first dance recital and decided she wanted to be onstage the rest of her life. Still, like most theater grads, she waited tables, catered parties and donned embarrassing costumes for bank openings while auditioning and appearing in bit background parts for film and TV.

Her first stand-in job was on the FX thriller “Damages,” about 10 years ago. She was given a script and watched the actors rehearse one scene before she was asked to stand in for a guest star, so the crew could set up the lights and mikes while the actors got their hair and makeup done.

Doubling was more interesting than background work.

“It’s a fairly easy job, but to do it really well, you have to think on your toes,” she says. “Sometimes we’ll do a whole scene with dialogue because [the crew] wants to see the full range of motion. Sometimes they’ll have you go from mark to mark. Sometimes you’ll have to be standing in for three characters in the same scene, and you’re like, ‘How does this work?’ — especially when they’re all talking to each other.”

She stood in for a then-unknown Robbie in the short-lived TV show “Pan Am” and an 80-something June Squibb in Adult Swim’s “The Jack and Triumph Show.” Some of her more challenging bits of business: blocking an oral-sex scene with another woman in “Orange Is the New Black.”

Since the #MeToo movement, she says, “Casting has gotten much better about giving us a head’s up if there’s a scene of a violent or intimate nature.”

But for “Russian Doll,” Sorensen didn’t only block a scene: She was actually on camera. When Lyonne was busy with several aspects of the shoot, Sorensen was mimicking her slapstick movements, assured swagger and honking New York accent. She also played a bartender in a couple of other scenes.

“It was a totally unique experience,” Sorensen says. “Especially since it was such a personal project for Natasha. I really wanted to be there for her.”

Lyonne says she had full confidence in Sorensen. “Our seven years together on ‘Orange Is the New Black’ created a sort of telepathy between us,” the star says, adding that Sorensen could anticipate her choices before Lyonne knew she’d make them. Having her on “Russian Doll,” Lyonne adds, “was like having a most trusted ally and doppelgänger, which, on a show already built on the pretense of multiverses and loops, was particularly handy.”

Now that “Russian Doll” has wrapped, Sorensen is shooting the last season of “Orange” and working on post-production on “As One,” a film she directed and wrote.

And she’s still getting used to seeing Lyonne’s comments — fire emojis and all — on her social-media posts.

“She’s always joking, but every now and then she gets really sincere and she’ll be really appreciative,” Sorensen says. “I’m just honored that she trusted me to be part of this journey for her.”