"From a young age, I was always buying and selling stuff. I was buying stuff from China and selling it on Trade Me and Facebook," she said.
Liu said her experience in buying and selling things from her teenage years helped when she started her first business: I'll Take All Three.
While the clothing business "failed within three months", Liu said she was able to use the same processes when she launched Waist Trainer NZ AUS five months later.
"I saw the waist trainer product online and I really wanted it, and I thought other people like me would want it, too, so I thought 'Okay, I'll just add another product', and that sort of just took over from the clothing," she said.
"I didn't have much after my first clothing business failed (which I put about $25,000 into, and ended up selling off all the stock slowly over time).
"I remember spending about $6000 on stock initially and ran the business from home so basically had no expenses."
Liu was surprised at how fast Waist Trainer NZ AUS took off.
She was 21 years old at the time and fresh out of university. Now, after 18 months of hard work, Liu is enjoying the fruits of her labour.
Her first luxury purchase was a new $240,000 Mercedes Benz G55. She has since bought a piece of land to build her dream home on and put an offer on a luxury five-bedroom Coatesville property.
"Next year I really just want to focus on building my house, and focus a little bit more on my personal life because this past year and a half has been spent focusing on the business," Liu said.
Iyia Liu (centre) and the team at Waist Trainer NZ AUS and Luxe Fitness.
Liu studied a Bachelor of Commerce at the University of Auckland, majoring in marketing and management. While she said it did help her strategy, it was through trial and error she credited to her business success.
"I felt like some of the theory taught me how to think. Theory is always different to real life. You learn most of the things along the way."
Waist Trainer NZ AUS sells waist trainers imported from China to more than 90 countries and receives "hundreds of orders a day".
Within a year, the brand turned over $3.5m, delivering her almost $1m in profits.
Persevere and just keep trying. My first business failed very quickly, within a few months, but you just have to move forward and keep trying.
Growth within the initial months was "incredible", she said. "I went from having just me to having eight staff within three months. It grew so quickly."
"With Waist Trainer I didn't foresee it getting to this stage, ever."
Liu has since cut down to four full-time employees.
Now that Waist Trainer is established, Liu says fitness brand Luxe will be her main focus in the new year.
"Waist Trainer and Luxe Fitness do have a similar target market, you know health, fitness, weight loss, so they do link up and we can cross-promote them."
YouTube star Shannon Harris is an ambassador of Luxe Fitness protein powder.
The company sells the most product to Australia, closely followed by New Zealand and the United States. For Luxe Fitness, a tea and new protein powder flavours are among new products set to launch next year.
"I think Luxe Fitness has a lot of expansion possibilities; there's a lot more we can do with the brand in comparison to Waist Trainer," Liu said.
"I just want the business to continue to expand. I love to watch it grow, putting in new products, trying all sorts of things; it's really interesting."
So what's the formula to her success?
"If you have an idea in mind just try it because you never know where it can go.
"Persevere and just keep trying. My first business failed very quickly, within a few months, but you just have to move forward and keep trying."
• Age: 23 years old • Born: Auckland • Role model: Kylie Jenner • Currently reading:Girl Boss by Sophia Amoruso • Focus of 2017: Expanding Luxe Fitness • Business advice: Try new things; persevere and keep trying
