Katharine McPhee Is 'Calm' Hours Before Wedding to David Foster Thanks to Facial and 'a Little Xanax'

Katharine McPhee has found the secret to bridal bliss.

The singer and actress is set to tie the knot to musician David Foster, 69, on Friday and shared a video of her pre-wedding beauty prep leading up to the big moment.

McPhee, 35, posted an Instagram story getting a facial by Hasti Parangi writing that a relaxing self-care session is “the secret to a calm and collected bride.” She added: “And maybe a little Xanax.”

She thinks it’s so relaxing in fact, that she doubled up on her skincare treatments. Shortly after her facial, McPhee shared another selfie wearing a Charlotte Tilbury face mask captioning the pic, “chilling.”

To commemorate her wedding day, she also posted a video of herself performing “Somewhere Over The Rainbow” with Foster playing piano in the background.

“Exactly 13 years ago today my very first single, Somewhere Over The Rainbow, was released right after Idol. Today… I’m marrying the man who produced it. Life is full of beautiful coincidences, isn’t it? Thank you for taking me over the rainbow, David. ❤️”

On Friday, just before the ceremony, her soon-to-be daughter-in-law Erin Foster, 36, shared a video to her Instagram Story featuring herself and her family dressed up in the car, winking playfully at the camera. Sister Amy Foster, 45, who was recently diagnosed with breast cancer, also shared a video of herself receiving an IV drip. “She ready for the wedding!” read the text on the clip.

When it comes to her fashion for the big day, it appears that her friend Zac Posen may have designed a custom dress for the star.

On Thursday, the designer shared a snap of himself with McPhee and songwriter Carole Bayer Sager. “Fun times in London,” he captioned the photo, also tagging Foster and adding the bride emoji.

The couple got engaged last July while they vacationed in Anacapri, Italy. This will be the second marriage for the American Idol alum, who was previously married to Nick Cokas, and the fifth for Foster, who was most recently married to Real Housewives of Beverly Hills star Yolanda Hadid.

The couple first met in 2006 when Foster mentored McPhee and other contestants on season 5 of American Idol, and after reconnecting, kept their relationship quiet in the beginning. But since getting engaged, they can’t help but rave about one another.

“We’re so happy and proud of each other,” McPhee gushed to PEOPLE in May.

Last fall, she shared a similar sentiment, telling PEOPLE in September, “We genuinely love and respect each other and have for a very long time.”

Leading up to their upcoming wedding, the couple has been vacationing across Europe. They first spent time in Lake Como, Italy before heading to Greece, where McPhee shared a series of silly and sexy pics from their time aboard a yacht in Mykonos.

She also shared a fun slideshow of photos wearing an ‘80s-inspired get-up, complete with a rainbow tutu, colorful jewelry and fuchsia bow, during their yacht trip.

“Honey this is how you throw a party in Mykonos bitch!!” she captioned the post.

Foster didn’t share any pics in Greece, but did post a pic of himself during their time in Italy wearing a pair of ripped white pants and a long-sleeved light blue shirt sitting on a bench.