Francisco Rivera's "original plan" after college graduation was to work in music and travel.

But after he finished his degree in music production at Full Sail University in 2017, he couldn't find a job in the industry. So, Rivera made money where he could: He worked in an Apple Store, then nabbed a part-time gig for online tutoring company Outschool.

Those jobs weren't satisfying or lucrative — at least compared to what he does now, he says. In February 2023, Rivera started selling print-on-demand candles on Etsy. At first, he worked four to five hours a day, and only brought in a couple hundred dollars a month.

Two months later, Rivera was on a date when his side hustle catapulted into popularity: He received over 70 orders that day, compared to his usual 10, he estimates. "I was so distracted because my phone wouldn't stop buzzing."

Now that Rivera's shop is up and running, and has garnered over 5,000 reviews on Etsy, he only has to work 20 minutes a day to manage customer relations, he says. Last year, he brought in $462,000 in sales, according to documents reviewed by CNBC Make It. That averages to roughly $38,500 per month.

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Rivera estimates 30% to 50% of each sale is profit. The remaining cash pays for Etsy fees, which were nearly $55,000 last year, and marketing and Printify, the service he uses to connect with manufacturers. (Rivera asked to keep his shop's name private, so other sellers don't copy his products.)

The success of Rivera's Etsy shop allowed him to quit his tutoring job in December. This year, he's used his extra time to travel the world — he just returned from Bali — and work on personal music projects, he says.

"Some people love structure ... but I just recognize that wasn't for me," Rivera, 26, tells CNBC Make It. "Being my own boss is very fulfilling."

Here's how Rivera honed his skills from past jobs to open a successful shop, and how he stands out in a saturated print-on-demand market.

Leveraging existing skills

After college, Rivera worked in Apple stores in the Dallas-Fort Worth area for three years. There, he learned how to multi-task, build relationships and solve customers' problems, even when people yelled at him, he says.

He moved to Orlando, his hometown, in 2020. There, he took the job with Outschool, where he taught 7- to 12-year-olds how to build social and critical thinking skills on the popular online game Minecraft. The pay was good, up to $100 per hour, and it was his introduction to online businesses, he says.

Rivera started seeking new ways to make income when demand for online tutoring waned after the pandemic, he says.

That's when he stumbled on a YouTube video about print-on-demand. The popular side hustle has a simple concept: Sellers create designs for products like T-shirts, tote bags or mugs, then list the designs on online marketplaces. After an order is placed, a manufacturer prints the design onto the product and ships it directly to the customer.

As Rivera did more research, he realized just how many people were already selling apparel. More competition, another YouTube video informed him, would make it harder for his shop to go viral.

He scoured Printify's catalog for more ideas, and landed on candles — a relatively new and less popular product, he figured — even though he's allergic.

"I wanted to make an aesthetic, neutral candle that could fit into any space. I also love humor [so] I liked the idea of brainstorming phrases for specific niches," he says.

His customer service skills also likely helped his shop quickly accumulate positive reviews and bolster his reputation on the platform, he says. (Etsy doesn't disclose how its algorithm ranks its search results, but its seller's handbook says shops need "fabulous feedback" to be successful.)

Trial and error leads to a winning formula

Rivera experiments with strategies, learned through trial and error and YouTube tutorials, to help his Etsy store stand out, he says.

He alters his product descriptions, updates product photos and invests in internal marketing on Etsy to get his candles in front of as many users as possible, he says.

It's not an expensive model: Listing each product on Etsy costs $0.20, then the platform takes 6.5% of every sale. He borrows someone else's Canva account, but the Pro version costs $120 per year.

Rivera's side hustle model is simple as well. He starts with a photo of a candle with a blank label, adds a phrase — like "Smells like a Promotion," which is popular for other sellers — on Canva. Then, he uploads the design to Etsy, and his linked Printify account sends the design to a manufacturer who ships the final product directly to customers.

While traveling, Rivera still works less than an hour per day. When he's home in Orlando, he dedicates two hours at least one day per week to researching platform trends, he says.

The research phase is time consuming, but crucial to his success, Rivera says. He spends that time figuring out how to appeal to hyper-specific groups like hockey moms, new parents who hate dirty diapers, bridal parties, divorcees and people in long-distance relationships.

"I don't technically have to work every day ... You can [make this] passive all year round if you want to," Rivera says. "You're just not going to make quite as much."

Rivera is considering expanding the business, potentially leaning into his tutoring expertise to produce his own print-on-demand YouTube videos, he says — but it comes with a cost. He'd have to give up his free time, and therefore, a slice of his music and traveling pursuits.

"There's value in time and value and flexibility," Rivera says. "I would take a pay cut if it still allowed me to do what I'm doing [with my free time]."

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