Dr. Ruth gives her latest advice on loneliness in her book The Joy of Connections

Towards the end of her life, America’s most famed sexologist, Dr. Ruth Westheimer, stopped talking so much about sexual dysfunctions and began to address another topic, one often shrouded in shame: loneliness.

She believed she was ideally qualified to confront the ongoing epidemic of loneliness. A German Jewish refugee whose parents died in the Holocaust, she had been twice divorced and then widowed. Dr. Ruth understood loneliness.

But she also believed that her education in sexology helped her cope with the humiliation of loneliness.

“No one is excited to admit they have problems in the bedroom,” Dr. Ruth wrote in “The Joy of Connections,” her latest book, to be released on September 3 — less than two months after her death at age 96. “No one is excited to admit they have too few reliable friends. Shame is the thread that holds them together, and shame is what I have always tried to aid people overcome.”

The Joy of Connections is essentially a list of 100 strategies for building stronger connections, based on Dr. Ruth’s belief that loneliness is nothing to be ashamed of and her intolerance for wallowing in despair.

“You can,” she urged, “decide that being alone is no longer an option.”

“She’s all about agency,” said Allison Gilbert, one of the two authors with whom Dr. Ruth wrote her novel book. “She’s all about taking steps to get where you want to go, not waiting.”

Here are Dr. Ruth’s final five lessons on building connections.

1. Be a turtle.

Dr. Ruth’s Manhattan apartment was filled with hundreds of miniature turtles — most of them gifts from family or friends — that crowded her bookshelves and coffee table to the point that there was no room for an actual cup of coffee.

Turtles weren’t just her favorite animal; they were her favorite (if not subtle) metaphor. To live a full and connected life, you have to stick your neck out. “A turtle can’t hunt for food, bask in the sun, or find a mate if it plays it sheltered forever,” she wrote. “Turtles have to take risks to live.”

2. Losing count.

As a single mother with no money for a babysitter but a mighty need to stay connected to friends, Dr. Ruth got into the habit of hosting parties—becoming, as she calls it, “the perpetual hostess.” But rather than resenting the fact that she usually had to initiate the plans, she began hosting because it made her feel less isolated.

“I myself was caught up in the mental arithmetic of how many times I was hosting versus how many times I was invited to places,” Ms. Gilbert admitted. “Your goal at the end of the day is not a ledger that seems more even. Your goal at the end of the day is to surround yourself with people you really want to be with.”

3. Expand your circle of friends.

Many of us cling to the idea that our best friends are, well, the best friendships to cultivate, but Dr. Ruth believed it was critical to pursue all kinds of platonic connections. Work friends. Friends of friends. Casual friends. (Indeed, research shows that frail ties can aid boost well-being.)

And do not discriminate against anyone based on gender, age or sexual orientation, she wrote.

Debby Herbenick, a professor at the Indiana University School of Public Health, recalled how Dr. Ruth made an effort to connect with her colleagues. As a youthful mother, she attended a business lunch with Dr. Ruth and had a baby with her. The world-famous therapist doted on Dr. Herbenick’s child like an ancient family friend, she recalled. “After she died, I saw other people in my field saying, ‘Oh, yes, we did this together, but she was more interested in my daughter.’”

4. Make your city smaller.

When Dr. Ruth moved to Fresh York, she immediately felt the need to make the large city seem smaller. “I had to work extra challenging to introduce myself to my neighbors and make meaningful connections,” she wrote. She joined community organizations. She chatted with neighbors in the elevator, occasionally taking the opportunity to ask them about their sex lives.

“Have you ever been to a block party? If you didn’t come out of your living room next week, would anyone wonder where you were?” she suggested asking herself. “If your answer to any of these questions is no, you need to change your away status immediately.”

5. If you feel lonely, say it out thunderous.

Dr. Ruth worked as a behavioral therapist for decades. She described her approach as direct, quick, and practical. And she believed that many of her clients began to heal almost the moment they admitted they had a problem. So if you feel alone, say it—out thunderous.

Take comfort in the thought that while it may seem like everyone around you feels fulfilled by their relationships, most people feel lonely at some point in their lives.

“I know,” Dr. Ruth wrote, “that if we talk openly about loneliness—without apology or euphemism—those who feel painfully disconnected will feel less lonely, too.”