Megan Sauer

This story is part of CNBC Make It's Six-Figure Side Hustle series, where people with lucrative side hustles break down the routines and habits they've used to make money on top of their full-time jobs.

Part-time nurse Megan Walsh uses her Etsy side hustle — which currently brings in six figures per year — to help pay a variety of bills, large and small.

Mark Cuban knows what sets successful people apart from the crowd.

The day Lisa Collum started her side hustle in 2011, she went to OfficeMax and bought five binders with the last $99 in her checking account, she says.

Jenny Lei, 28, is the founder and CEO of Freja, a company that sells work totes, shoulder purses and travel accessories. The 4-year-old startup brought in more than $9 million in revenue over the last 12 months, including $2 million in profit. Here's how Lei built a trendsetting brand, despite her lack of experience in the industry.

Jenny Lei looked at the towering stack of cardboard boxes in her Hoboken, New Jersey, apartment. She'd spent $30,000 on handbags and needed a new strategy to sell them.

More than a third of all U.S. adults have a side hustle recent data shows . The people who make the most money have something in common: lots of emotional intelligence

Lexi Tobin was always "the planner" among her siblings and friends. In 2019, Tobin helped her brother-in-law to-be plan his proposal.

Lexi Tobin brings in over six figures per year planning people's proposals and posting their reactions on TikTok.

This story is part of CNBC Make It's Six-Figure Side Hustle series, where people with lucrative side hustles break down the routines and habits they've used to make money on top of their full-time jobs.