Cassiy Johnson's side hustles help her make more money without a college degree than she ever expected.

In March 2020, Johnson was furloughed from her daycare sales job. A YouTube video told her that a "print-on-demand" side hustles was, in her words, a "simple and easy" way to earn cash. So, she started creating T-shirt designs on her phone and posting them on Etsy.

In print-on-demand selling, people create designs on blank templates — T-shirts, mugs, tote bags — and wait for people to order them. Then, they send the orders to manufacturers, which print and ship each shirt upon request.

After a year and a half, Johnson's side gig earned enough revenue for her to leave her full-time sales job. The 31-year-old leveraged the business into three revenue streams: the print-on-demand shop, another Etsy store called StopMockAndRoll and a YouTube channel, where she teaches her 126,000 subscribers how to duplicate her efforts.

The YouTube channel is currently the most lucrative, Johnson says. And the print-on-demand store brought in more than $766,000 since 2020, according to documents reviewed by CNBC Make It. In its most successful month, she sold $100,900 worth of T-shirts and mugs on Etsy.

Johnson estimates a third of her store's revenue was profit, until she closed the shop earlier this month. A publicity-led influx of views lowered her store's sales conversion rate, jeopardizing her spot in Etsy's search algorithms, she says. (Etsy didn't immediately respond to Make It's request for comment.)

She's already started a new print-on-demand store, she says. It's all a big turnaround from her life pre-pandemic: "I'm going to make scraps without a degree," she recalls once telling herself.

A 'first taste of being successful'

Johnson grew up in Howell, Michigan, a rural town bordering Thompson Lake, an hour's drive northwest from Detroit. She became pregnant at age 16, dropped out of high school and worked odd jobs — at fast food restaurants, movie theaters, roller rinks — to pay her bills.

She got her GED, and at age 19, her "first taste of being successful at something" when she was hired as a salesperson at Art Van, a now-closed Midwestern furniture store chain. The job, she says, changed her life.

It was invaluable to have a manager who believed in her. She felt she made a difference in people's lives, efficiently helping them find what they wanted. After a couple years, she was regularly her store's top salesperson, she says.

"Without knowing what you're good at, it's hard to be a confident person," says Johnson, adding: "I watched everyone I went to high school with go to college and start careers while I was a single mom struggling to make ends meet."

By the time Johnson launched her Etsy store, she was making $70,000 per year as a salesperson. It was the "worst job" she ever had, but it offered enough benefits for her to support her family, she says.

"I started looking for a 9-to-5 type job that paid better, but there isn't much for people without degrees," she notes. Instead, she found something else she was good at, helping her leave the world of sales entirely.

The value of confidence

Confidence really can make you more successful, according to leadership experts.

It's the key to making "very impactful decisions," whether you're a manager or an entry-level employee, Bonnie Low-Kramen, author of the 2023 book "Staff Matters," told CNBC Make It last month.

"Confidence is very serious business, and the single most important differentiator in the world place," Low-Kramen, a workplace expert and CEO coach, wrote in her book. "It will be the person with the high confidence and lower abilities who will get the job over the person with low confidence and higher abilities."

Johnson leans into that confidence while running her three businesses.

"I'm not a magical unicorn," she says. Rather, she adds, her background and the self-help business books she started reading at age 19 taught her how to cultivate a "winning mindset," effectively set and achieve goals, and help customers find what they want.

"I'm sure [my past has] given me some grit," says Johnson. "I think that's what really sets me apart. I'm not afraid to put in the hours, and I don't have the expectation of like, 'What if I fail?' So what if I do? Then I'll find out."

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