A day in the life of one of Etsy's most prolific sellers — a 31-year-old who turned her side hustle into a full-time business

One of the most pervasive career trends today is the art of the side hustle.

Discovering a way to monetize your passions or hobbies, whether it be photography, writing, knitting, consulting, you name it, is a fulfilling way to earn some extra cash. Sometimes though, it becomes lucrative enough to pursue full time.

That was the case for 31-year-old Sara Barrett. After graduating from the Massachusetts College of Art and Design in 2007 with a degree in graphic design, Barrett started doing freelance work, creating wedding and baby shower invitations.

In 2009, a client suggested she list some of her artwork on Etsy, an online marketplace for creative sellers and buyers, she told Business Insider. She thought, "'What have I got to lose?'" and set up shop as SimkaSol.

After Etsy customers began requesting her paper prints on pillowcases and clothing, Barrett taught herself to screen print "by the grace of the internet."

Take a look inside her daily workflow:

"I started learning how to pattern draft and how to use all my industrial sewing machines and it's kind of just been this continual chain of learning a new trade and applying it and then learning another step, just constantly chugging forward," she said.

Barrett kept up with the freelance graphic design — as well as teaching horseback riding lessons — until she realized how lucrative her Etsy shop had become. "It really wasn't until late 2011 where I was like, 'Wow, I'm making enough money to pay all my bills and invest back into the business. So at that point I was like, 'I'm going to go for it," she said. Today, SimkaSol remains Barrett's main source of income.

To date, SimkaSol has raked in more than 16,000 sales on Etsy — and more than 47,800 "admirers" — which accounts for about 80% of Barrett's overall business, she said. The other 20% comes from selling a full collection of women's and men's clothing and home decor on her personal website.

Five years in and Barrett is still the sole employee of her company — aside from a little help from her friends during the holiday season. Business Insider recently caught up with Barrett at her in-home production studio in Massachusetts, where she walked us through a day of one of Etsy's most prolific sellers.