“I’ve gone full Victorian,” said Rhian Rees, 34, of flower pressing, a childhood hobby she’s rediscovered in quarantine. “It feels like we’re back in the old days when life felt more fragile.”

On a recent hike in Santa Clarita, Calif., Ms. Rees, an actor originally from England and now living in the Los Feliz neighborhood of Los Angeles, brought home an assortment of seedlings and delicate, small blossoms and leaves. Some she dried out in silica gel and later set inside blocks of polyester resin, while others were placed inside an old fashioned flower press that had been gathering dust on her bookshelf, and others in between the pages of a book on 19th-century Shaker-style homes and interiors. The dried and flattened flowers were later affixed to notepaper that Ms. Rees used to write physical letters to family members and friends sequestered elsewhere. (Some of those letters were to offer condolence. Ms. Rees has lost an uncle to Covid-19, as well as her husband’s godfather.)

With 26 million people applying for unemployment benefits in the last five weeks, and others furloughed or with hours freed from commuting, many are finding themselves with more leisure time, wanted or not. Some are turning to virtual versions of their favorite pre-pandemic activities: digital dance raves, game nights and exercise classes have all popped up since lockdown began.

But others are cutting down on screen time by pursuing old-timey crafts of a bygone era: namely the Victorian times of 19th-century England, when greater wealth and industrialization afforded the privileged upper class more idle time to hang out at home. The new leisure class filled their down time with activities like fern collecting, flower pressing, scrapbooking, board games and playing chamber music on their own instruments.

Ms. Rees said her landlord has let the grass in their shared garden grow wild.

“There’s lots of little clovers out there,” she said. “So I have been trying to find some four-leaf clovers.”

Before the pandemic brought London to a halt, Lucy O’Farrelly, 19, worked as a production assistant at a design house specializing in children’s clothing and stationery. Most of her mornings were spent emailing with manufacturers in China. Because no samples are being sent out at the moment, she has been furloughed.

“Having time away from that has been great,” Ms. O’Farrelly said. “People are just wishing to avoid screens.”

She is using her free time to pursue her own favorite Victorian-era pastime: collage. Unlike the goal-oriented activity of creating a vision board to manifest one’s heart’s desire, collage has no purpose other than creative release.

At the moment, Ms. O’Farrelly is growing tomatoes and cucumbers from seed. She plans to preserve their leaves in her mother’s vintage flower press and use them in the pages of a new collage book given to her by her best friend, jumbled artfully together with magazine clippings, decorative paper scraps, dried rosebuds and lines of original poetry.

“You’re just sticking stuff down and whatever happens, happens. It’s relaxing,” she said. “We’re sort of going back in time a bit. I’m definitely here for it.”

In the 19th century, intellectuals like Johann Wolfgang von Goethe and others started to expand on the positive psychological benefits associated with a concept now known as mastery: practicing an activity at which you have no previous level of expertise, and experiencing gradual improvement over time.

Today, mastery and deliberate practice are areas of focus for Anders Ericsson, author of “Peak: Secrets From the New Science of Expertise,” and a professor of psychology at Florida State University. “The ability to generate activities by yourself for yourself, that is a real asset,” said Mr. Ericsson, 72, in a phone interview. He has been spending his leisure time poking around on Google Scholar, identifying new information he does not yet know. “That is sort of like play for me,” he said.

“During the Second World War, when people were in concentration camps, many prisoners developed impressive skills at mental multiplication,” he said. “They were in such an aversive environment, pushing themselves to solve problems felt like an escape, when they had no resources.”

Even in less extreme situations, it can be empowering to experience improvement, in any small or large area of life, especially in a period when many are feeling stuck both physically and emotionally.

“Once you acquire a skill, there are activities you can do that are much more enjoyable,” Mr. Ericsson said, referring to the delayed and deeper gratification that comes from meeting resistance and overcoming obstacles, versus the more passive rewards of activities requiring minimal effort or discomfort, such as Netflix. ”Once you experience what changes you can accomplish, that changes your perception of what’s possible, it changes your mind about what’s possible.”

In Brooklyn, Tom CJ Brown, 35 and also originally from England, had dreamed of playing “Clair de Lune” on the harp, but didn’t own the string instrument, which was popularized in its modern form by a Chicago shop in 1889 but not exactly easy to acquire on Craigslist.

Mr. Brown, an animator and filmmaker, hasn’t worked since mid-March. Despite seeing an initial bump in demand for animated advertisements after Hollywood shut down live-action productions, he said that jobs have dried up in recent weeks, and he’s had to find novel ways to fill his idle time indoors.

“I definitely knew that I wanted something that I could do that didn’t feel a lot like work,” said Mr. Brown. “I was just like, ‘I think I need something that will take a lot of time,’ and I wanted something that was completely nondigital.”

YouTube tutorials on harp-playing abound, and a local woman in his neighborhood was even offering classes on Zoom. But first he’d need the instrument. Daunted by even secondhand prices, Mr. Brown decided he would build the harp himself. On Etsy, he found the $159 Fireside Folk Harp kit, a 22-string instrument with a cardboard soundbox and many slow steps toward assembly.

“It just felt like an opportunity to see incremental progress,” said Mr. Brown, who documented the project on Instagram. “Putting layers of paint on a piece of wood. Literally watching paint dry: this is the perfect thing.”

Mr. Brown placed the order for his Fireside Folk Harp, which was shipped from Hamden, Conn., on March 23. It arrived a week later, and he completed the project on April 16.

“It looks like I built it in 12 days. It’s not 12 hours, but I’m not Windmaster5000,” he said, referring to a faster harp-builder on YouTube.

While he’s not yet mastered “Clair de Lune,” Mr. Brown has already learned to play “Mary Had a Little Lamb,” to the delight of his 2-year-old nephew.

“Now the harp is finished, I’ve taken to staring at the Chrysler Building hoping to see the lights turn on,” he said. “It’s fun, but it’s not the same.”

Erika Urso-Deutsch, 34, is a Catholic school art teacher and private chef in Easton, Pa. While she has adapted to distance learning, teaching her kindergarten through eighth-grade students online via Zoom, Mrs. Urso-Deutsch has found time to pursue a project she had put off until the pandemic forced schools to close: natural dyeing.

She was making herself a cup of “golden milk” — a beverage combining milk (or nondairy milk) with turmeric, cinnamon and other spices — when she got the idea.

“My hands were stained so yellow when I was done, so then I was like, ‘Wait a minute, if this is staining my hands, this is what I’m going to use to dye eggs,’” said Mrs. Urso-Deutsch, who began with a batch of hard-boiled eggs for Easter.

From there, she decided to expand the project, creating batches of natural dyes with the turmeric powder, which creates a bright golden dye; paprika powder, for red dye and dried hibiscus flowers, for magenta dye.

“It is something I’ve wanted to try for probably 10 years, and I never had the time,” said Mrs. Urso-Deutsch. “Most of our dyes used to be botanically based — made from fruits, flowers, roots and such. So it’s really a return to a lost art.”

Mrs. Urso-Deutsch’s Easter eggs were a success, and so she was inspired to advance to a more ambitious project of dyeing old textiles, including a set of stained linen napkins passed down through her family. The napkins were given a new life after soaking in batches of boiled purple cabbage water creating a violet-blue color, as well as the turmeric and a batch of rust-colored dye made from red onion skins.

From there, she dyed lace curtains and doilies, a knitted dress, a crocheted vest, an old apron and yarn for knitting, all in a rainbow of pinks and purples and goldenrod.

“I know that when this ends, I’m going to feel good about the way I’ve used my time,” she said. “We can only control what we can control, and right now that’s our own selves.”