While everyone else was getting ready for the 2018 Emmys, Jennifer Garner was doing some beauty prep of her own on Sept. 17. But it wasn't to get herself ready for television's biggest night.

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Instead, Jen was filming some fun (and funny) support for her good friend Reese Witherspoon to celebrate the release of Reese's new book, "Whiskey in a Teacup." Jen, you see, decided to practicing hot-rolling her hair using Reese's tips outlined in the book.

"My friend @reesewitherspoon has written a book full of so much -- great food and recipes, insights, family, life lessons. It's so so fun, check it out! Oh, and her hot roller tips are 🌟 🌟🌟," Jen captioned the ridiculous video, adding the hashtags #WhiskeyInATeacup #availabletomorrow #improudofyoulady and #belikereese.

The clip starts with Jen looking at her pal's step-by-step photos. "How to hot-roll your hair," she says, reading from the open book. "To this day, it's the only way I know to do my hair." Jen agrees: "Me too."

"I can't blow out my hair," she says, continuing to read Reese's words, adding "Me either." Then, "I can't straight-iron it." Jen: "No." When Jen reads the instructions that say to "apply mousse," she looks around for the hair product that was at the height of popularity in the '80s.

She continues with the instructions: "Roll your hair into the heated rollers and clip 'em down." Finally, Jen has some success: "Well, I can do that!"

Next instruction: "Get into the car and go where you're going with the rollers in your hair," Jen reads then adds, "Well, good, I have school pickup in just a minute! So far so good."

@jennifer.garner / Instagram

She's then seen driving through the streets of Los Angeles with a head full of bright purple hot rollers on her way to get kids Violet, Seraphina and Samuel Affleck. Referencing the book again, she realizes she's done something wrong: "I'm supposed to have the window down, sorry," she says.

During this, Jen -- who's otherwise makeup-free -- is wearing a bright red shade on her mouth. "[Reese] added a red lipstick, so this is as close as I get," Jen says as she shows off an impossibly glamorous photo from the book that shows Reese driving while wearing hot rollers in her hair too.

Finally, Jen says, "I'm at my destination" and takes out the purple hot rollers one by one and fluffs her voluminous locks before turning to the camera to ask, "Do I look Southern?" The West Virginia-bred actress then squirts her hair with hairspray -- aerosol, of course -- and concludes, "That's gonna have to do it! Boy, are my kids gonna be surprised. Thanks, Reese!"

@jennifer.garner / Instagram

She posted a few outtakes on her Instagram Story as she rides through L.A. with curlers in her hair, commenting on seeing several limos and chauffeured vehicles. "There are so many fancy cars because everyone's getting ready to go to the Emmys," she explains to the camera before setting up a joke.

"I can't remember if I'm going. Let me call [my hairdresser] Adir [Abergel] and tell him not to worry about coming over -- I've done my hair! I've got this," Jen quips.

Jen might have turned it into a playful joke but it's clear she's impressed with her old friend Reese, who's been promoting her new project on social media and on the morning shows. "Today, my first book ever, #WhiskeyInATeacup, is out. This book gave me an opportunity to reflect on growing up and all the traditions that I learned from my friends and family in the South," Reese captioned a shot of herself with the book hours after Jen posted about it.

"I've included some of the recipes that remind me of home, and are staples in my house, as well as no-fail tips and tricks that I live by," she added. "I'm so humbled from the experience of it all and honored to share it with you. πŸ’•"