Billionaires reveal the secrets of their success

Martha Stewart's secrets to success
Martha Stewart's secrets to success

What does it take to make it to the top? One common thread among business titans is the ability to slog through the eventual tough times and never give up.

This determination is one defining characteristic of those who made CNBC's 2014 list of the 25 people who had the most profound impact on business and finance since 1989, the year the business news network went live.

I don't need the money anymore...but I'm obsessed in getting something right.
Carl Icahn

But in interviews with several of the honorees, their other keys to success are as different and varied as their backgrounds and industries.

"Every one of these people broke out early. They knew what they wanted and they didn't take no for an answer," said Eric Schmidt, executive chairman at Alphabet, in a 2014 interview. He ranked No. 4 on the list, along with Alphabet executive team members Sergey Brin and Larry Page.

"They had this unusual sense of self-confidence and vision and they were willing to do whatever it took to achieve their business objective," Schmidt said.

Billionaire activist investor Carl Icahn said successful people seem to find themselves consumed by whatever they're working on. That obsession pays dividends.

"Just getting it right, you know, getting it done. Almost being a perfectionist," Icahn said. "Money is the scorecard. I don't need the money anymore ... but I'm obsessed in getting something right."

Martha Stewart credits her success not only to hard work, persistence and attention to detail, but also a keen understanding of branding.

"I had a friend called Charlotte Beers, who was a brander and she kept saying, 'Martha, you're a brand. You're a brand,'" Stewart said. "And then one day I woke up and said, 'Ah, I'm a brand.'"

Stewart used her namesake to create a domestic media empire and become the first female self-made billionaire in the United States, at least on paper. The founder of Martha Stewart Living Omnimedia, which merged with Sequential Brands Group in December 2015, ranked No. 24 on CNBC's list.

For Meg Whitman, chief executive of Hewlett Packard Enterprise and former CEO of eBay and No. 18 on the list, achieving success takes a lot of energy.

"Business is a full-contact sport, and it's hard," Whitman said. "It has always been for me about a team sport and who you have on your team and who your team members are, even if you're not the boss. And so it's the right person in the right job in the right time with the right attitude."