Two years after retiring from professional tennis, Serena Williams is busier than ever. She’s juggling a venture-capital fund; a new makeup brand, Wyn Beauty; a line of personal-care products, Will Perform; two young daughters; and an ESPN docuseries, In the Arena. Williams is also a brand ambassador for Lincoln and its new Navigator—her go-to S.U.V. In true multi-tasker form, Williams shares her nighttime routine and newfound appreciation for sleep.

When do you start getting ready for bed?
This is such a good topic. I was actually going to post about it yesterday. I get ready at around eight P.M. It’s early because I always do the bedtime routine with my oldest daughter, who is six. When she gets ready, I like to get ready. She still likes me to snuggle her sometimes.

TAKE US THROUGH YOUR NIGHTTIME SKIN-CARE ROUTINE.
I keep a couple of face washes in my shower because I’m all about multi-tasking and going fast. I even keep a toothbrush and toothpaste there. That way I can have a longer shower, too. At night, I don’t do a ton to my skin because I like to have the time to recover. I like to keep my skin pretty bare; sometimes I just do a moisturizer, sometimes I do a serum and no moisturizer, and sometimes I just do water. I keep my skin pure and clean.

HOW DO YOU DECOMPRESS AFTER A LONG DAY?
Mentally, I exit as fast as I can. I think I have decades of practice. If I’m done with something, someone will say, “How did it go?” I’m like, “Honestly, I think it went well, but I’ve moved on.” I don’t try to dwell.

WHAT KIND OF PHYSICAL RECOVERY DO YOU DO?
I need to stretch. I started trying to stretch, but I don’t have time for physical recovery anymore.

What’s one thing you do before bed?
I watch shows on my iPad. I don’t like the blue light of the TV. I wear these intense blue-light glasses at night, but they help me sleep better. I’m weird—I’m like the guy from Star Trek at night. They’re yellow with a bright orange lens.

WHAT do you watch?
I watch anything that shuts my brain off. Honestly, I’ll watch reruns of The Golden Girls or The Big Bang Theory—something that I don’t have to be stressed out from. If I watch a full movie, I’ll never sleep.

Do you take supplements?
I’m terrible with that. I should, but I don’t. I’m like “Why did I buy this?” There has to be a better way.

ON TO YOUR PAJAMAS …
Oh my gosh, my pajamas are so fun. We always get these random pajamas that are matching. Yesterday, Olympia had this Mickey Mouse set on, so I ran and put mine on. She loves when we wear the same thing. All three of us—the two girls and I—have this really cool matching set we got from France. The youngest has a onesie, Olympia has the pants and the top, and I have the little dress. It’s this white background with hearts on it. It’s so fun.

ARE YOU PARTICULAR ABOUT YOUR SLEEP CONDITIONS?
I like it cold. I like it dark.

HOW ABOUT YOUR BED?
I had a soft mattress, but my back was killing me, so I had to get a new one. It’s firmer. It’s not the most comfortable, but I have like zero back problems.

Where’s your favorite place to sleep?
My favorite place to sleep is on a massage table. It’s also my least favorite place, because I’m like, “Did you do my chest? Oh, you did? I didn’t feel it. Can you do it again?”

What’s the best night’s sleep you’ve ever had?
This is a true story. I was always the person who would do four hours and I’m good. I’m not a sleeper. For my entire life, I would go without sleeping. One time in Paris, just a couple of months ago, I went to sleep on the massage table. Every morning I was like, “I’m going to get a massage, so I can go to sleep because I have kids and I don’t sleep.” So, I would wake up at seven A.M., get a two-hour massage. I’d go down in my robe and just fall asleep. Ever since then, I’ve been having the world’s greatest sleep. Now I go to bed at nine P.M. and I sleep until I eight A.M. I’ve never slept this much in my entire life.

Tamara Warren has written about cars and culture for The New York Times, Vox, and Elle. She is the founder and C.E.O. of Le Car media company