Jenny Eisler learned to knit in the first grade, and was good at it. She also did time as a Girl Scout, which imbued her with an admirable can-do spirit.

Consequently, when New York City locked down last spring to stem the spread of the coronavirus, and Ms. Eisler, 25, was stuck in her studio apartment in NoLIta without much to do, she impulsively ordered some embroidery hoops, needles and thread on Amazon, correctly betting that a creditable chain stitch was but a few YouTube tutorials away.

“The first thing I embroidered was the word ‘quarantine’ in green thread on my gray hoodie,” said Ms. Eisler, who works at an online fashion retailer. “I embroidered all my clothes,” she continued. “And then when I ran out of my own stuff to embroider I started embroidering things for my sister.”

Ms. Eisler decamped to her parents’ house in Scarsdale with her craft equipment as the pandemic took hold, began documenting her progress on Instagram and lo and behold, people started direct messaging her to place orders — 100 in the first few weeks — for tie-dyed custom-embroidered sweatshirts. “It just kind of happened,” Ms. Eisler said. “My friends all wanted them because everyone was at home and wearing sweat clothes.”

The coronavirus spawned an army of journal-keepers, sourdough seers, bakers, cooks, weavers, painters, gardeners and bird-watchers. For many, such hobbies have been a way to relieve boredom and stress, to give form to shapeless days. Ms. Eisler is among those who have turned pro — making their pandemic pastime an income-generating venture.

According to a recent survey by LendingTree, the online loan marketplace, close to 6 in 10 of the 1,000 respondents started a hobby during the pandemic; nearly half of them have earned money, turning it into a side hustle.

For some, it’s a pretty respectable figure. Ms. Eisler, who named her company Just by Jeanie (a tip of the hat to her plush rabbit) said that, so far, she has netted $20,000 from a product line that has expanded from sweatshirts to sweatpants, socks, baby blankets and onesies (short- and long-sleeved models).

Meanwhile, Lan Ngo, a pharmacist, banks $3,000 to $4,000 a month on sales of the dollhouse furniture she makes in the spare bedroom of her rental apartment in Clovis, Calif. And Jeff Neal, a project estimator for an industrial painting contractor, pockets $2,000 a month breeding crickets, roaches and other so-called feeder insects that he sells to amphibian and reptile owners, primarily through his website The Critter Depot.

Hawking crickets on the internet is an outgrowth of the hobby Mr. Neal started in the garage of his colonial house in Central Pennsylvania shortly before the pandemic, both to defray the cost of feeding the family’s very hungry bearded dragon, Monica, and to engage the interests of his three young daughters. (For the record, Mr. Neal’s wife is VERY grateful that it’s a detached garage.)

“On reptile forums, people were saying their local pet stores were closed because of Covid, and they were looking for feeder insects,” said Mr. Neal, who estimates that at the height of the pandemic, he was averaging between 10 to 15 orders per day and netting as much as $5,000 a month. (Critter Depot ships throughout the continental United States and provides instructions to customers about what to expect when receiving crickets in the mail.)

The futurist Faith Popcorn views all these enterprises as examples of several of the trends she has codified over the last several decades, among them “Down Aging,” (nostalgia for your younger creative self); “Truth to Power,” (coming out with your own thing and maybe not returning to the office) and “Pleasure Revenge.” “In this case,” Ms. Popcorn said, “it would mean really leaning into a hobby and thinking ‘I can make this. I can do this — and someone bought it on Etsy.’ ”

Just as the pandemic hit, Adam Sarkis, a Chicago-based entrepreneur, was walking away from a failed start-up.

“I started thinking about things I’d done as hobbies when I was younger, things I hadn’t had time to do in years,” said Mr. Sarkis, 35, who, when he wasn’t drawing in notebooks as a child, was playing basketball or watching basketball. “I decided to merge those passions and see what it looked like on canvas.”

Using acrylic paint, sponge brushes and Sharpies, Mr. Sarkis hunkered down at the dining room table in his South Loop rental and began painting head and shoulder images of carefully selected N.B.A. players. They included Latrell Sprewell, “because he was one of the first to wear dreadlocks that hung down his back,” and Dennis Rodman, “because he was one of the first to rock a lot of tattoos,” said Mr. Sarkis, who characterizes his style as a blend of Keith Haring and Jean Dubuffet.

He posted a few of his early efforts on Instagram, and was surprised and pleased to discover there was considerable interest in the prospect of owning an original Sarkis: “I was being asked for players like Ben Wallace, Steve Nash and Allen Iverson. It just snowballed.” So far, Mr. Sarkis said, he has sold more than 100 paintings.

But the will of the people forced him to shrink both the canvas (from 32 by 32 inches to 8 by 11) and the price (from $300 to $50). Even so, “I’ve definitely made more money than I put into it,” Mr. Sarkis said. “I understand pricing and overhead.”

There’s a lot to be said for having a tolerant family. “I’ve definitely made a mess throughout the house,” said Ms. Eisler, who has found in her mother, Denise, a willing and able tie-dying aide. “We put on old clothes, turn on music and go out on the deck to work,” she said.

When Tiffany Riffer, a product liability lawyer in Washington, started making soap as a pandemic pastime, she turned to her husband, Steve, a cybersecurity consultant, for help in the kitchen with the lye and essential oils. Tiffany Riffer Soap, in scents like lavender, eucalyptus and vanilla, is now available on line, and in a few stores in Washington and Virginia. Ms. Riffer is hoping to break even by the end of the year.

Mary Duque, 14, another soap maker, has taken over the dining room of her parents’ Cape Cod house in Easton, Conn. That’s where she stores ingredients and packing material, and where for two to five hours each week, she makes soaps, sugar scrubs, lotions and lip balms, all of which comprise her “Honey Bunny Soaps & Stuff” collection. Next up: sunscreen. “I’m pretty good at cleaning up after myself,” said Ms. Duque, who is planning to relocate to the basement soon. Meanwhile, meals are in the kitchen.

Involving her family was part of what motivated Ms. Ngo to start making dollhouse furniture in the first place. She wanted to get them started on a hobby too. “My father and sisters had a lot of time during the pandemic,” she said. “I was worried that if they stayed home doing nothing they would get depressed.”

The thing about a hobby, of course, is that you can spend just as much or as little time on it as you choose. No big deal if you’re not up for painting or drawing or embroidering today. But the calculus changes and so, sometimes, does the need for specialized equipment, when the pastime becomes a business.

Ms. Eisler works at her full-time job from 9 a.m. until after 8 p.m., then often switches over to Just by Jeanie tasks for an hour. Weekends are completely given over to tie-dying, an exceedingly labor-intensive activity.

Ms. Ngo, spends at least one day every weekend fabricating the tiny dining tables, chairs, doors, stoves and refrigerators she sells on Etsy. She finally bought a Glowforge laser printer (prices start at almost $3,000) after coming to the unavoidable conclusion that what she had made by hand with Popsicle sticks and cardboard was both labor intensive and not quite ready for prime time. Her family puts in about 20 hours each week, and when Ms. Ngo is trying to get out a big order, her fiancé lends a hand too.

For his part, Mr. Neal, the cricket breeder who works as much as 60 hours a week at his “real” job, is up daily at 4:30 a.m. every day to fill orders and answer emails. “I’m exhausted most of the time,” he said.

Fatigue notwithstanding, there’s something gratifying about the development of a new skill set. “It was eye-opening to dip my toe into entrepreneurship,” Mr. Neal said. “I had to solve customers’ problems, I had to do packaging and build a website. I found it really rewarding to chug through and make it happen without there being any catastrophe.”

Ms. Riffer, who hadn’t previously viewed herself as artistic and imaginative, is now rethinking the matter. “Making soap,” she said, “has been a way for me to be creative and to produce a product that was useful.”

And of course there is something extremely satisfying about people not just admiring what you make but admiring it enough to part with some money.

“It’s positive reinforcement,” said Gail Saltz, a clinical associate professor of psychiatry at the NewYork-Presbyterian Hospital.

“The overarching driver during Covid has been the need to find an outlet for play, for immersion in something pleasurable when we were stuck at home with a lot of stress and no outside distractions,” Dr. Saltz said. “You start a hobby. And then having people appreciate your hobby and say it’s worth something — that’s bonus points.”

Occasionally, the hobby that becomes the side hustle becomes the occupation. When Covid hit, David Angelov, a carpenter, was eager to find a pastime “that had nothing to do with other people,” he said.

His mother is a skilled and dedicated gardener. With her example in mind, Mr. Angelov, 24, decided to start clearing away the vines and brush that surrounded the three-bedroom contemporary house he shares with his father in Swampscott, Mass. “I got an appreciation for nature and how it was here long before us,” he said.

One thing led to another: Mr. Angelov began researching plants in his region, and the techniques for maintaining shrubs. He built a raised bed and planted vegetables, hauled in compost to amend the soil, pruned back the spirea and holly and spread wildflower seeds — all to very good effect. “It turned me into realizing that I could make some money off this,” Mr. Angelov said.

He put together a business plan for his company, PlantParent, last winter, and now tends 12 properties per week and fills in with some one-off projects. The ramp-up is slow, he added, “but gardening is proving more lucrative than carpentry.”

Still, for most, the hobby is going to stay the hobby. “For now, I like having the embroidery as my side hustle,” Ms. Eisler said. “I really enjoy my full-time job and have been able to balance the two nicely.”

Ms. Duque, the high school freshman, is keeping her options open. She’s been selling themed gift bags on Facebook and Instagram, and her grapefruit-rosemary lotion and exfoliating coffee soap have done a brisk business at Greiser’s, a market in Easton, which just put in an order for rosemary-mint and cucumber-melon soap. Ms. Duque was operating at a loss for a bit because of some pesky research and development expenses, “but I’m up now by about $320,” she said.

“It would be great to have a bigger business,” Ms. Duque continued. “I’m not expecting it to be like Dove or anything, but the fact that I started a little something is very cool.”

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