2018 Manage your money like the super-wealthy — 3 habits to steal from Warren Buffett, Mark Cuban and Kevin O’Leary

Even if you aren’t raking in millions, you can grow your wealth just by mimicking the financial habits and strategies of the ultra-rich. Here’s how.

Live within or below your means

Living within your means is one of the best financial habits you can master.

Take for example billionaire investor Warren Buffett, who currently boasts a net worth of more than $86.5 billion, yet still lives in the same house in Omaha, Nebraska, that he bought for $31,500 in 1958. Buffett is also famous for almost never spending more than $3.17 for breakfast and still uses coupons.

And Amazon founder (and richest person the world) Jeff Bezos still drove a modest, Honda accord even after gaining billionaire status.

Jay Leno, star of CNBC’s “Jay Leno’s Garage,” never used his income from NBC’s “The Tonight Show,” though he reportedly earned as much as $30 million a year. Instead, he continued to do stand-up gigs and lived off that. “I’ve never touched a dime of my ‘Tonight Show’ money. Ever,” Leno previously told CNBC Make It.

Why is it so important? Because it can help you stay out of debt and whatever you don’t spend you can invest, no matter how much or little that may be.

Kevin O’Leary, star of ABC’s “Shark Tank” and a personal finance author, still uses the strategy though he’s worth multimillions: “What has really helped me in maintaining growth in my own personal investing is, anytime I pick up something I’m going to buy, I say to myself, ‘Do I really need this?'” O’Leary says.

“Because if I don’t buy it, the money is going to be invested and make money every year for me while I’m sleeping.”

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Indeed, O’Leary even refuses to spend $2.50 on a cup of coffee, making his own at home instead.

Pay off debt

While some debt might seem necessary — whether it’s to pay for college or to pay for a car to get you to and from your job — in general, the wealthy advise avoiding debt in all ways possible.

“Shark Tank” star and tech billionaire Mark Cuban has had his fair share of struggles with credit card debt, in particular. Now, he advises others to nix credit cards and pay off any balance because the money saved on such high interest rates is better than any return you’ll get from investments.

The same is true for other debt too, he says.

“Whatever interest rate you have — it might be a student loan with a 7 percent interest rate — if you pay off that loan, you’re making 7 percent. That’s your immediate return, which is a lot safer than trying to pick a stock or trying to pick real estate, or whatever it may be,” Cuban says.

O’Leary agrees: “If you want to find financial freedom, you need to retire all debt — and yes that includes your mortgage,” he previously told CNBC Make It.

“Debt is evil,” he says.

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Don’t just save, invest

While saving your money instead of spending it is a good habit to get into, the ultra-wealthy know that the real road to riches begins with investing.

O’Leary — who tells CNBC Make It he invested in his first stock in 1982 when he was in his 20s and not yet rich — preaches the importance of investing to take advantage of compounding returns.

“When you’re 21 years old, or 20 or 18 or 19 and you start putting aside 10 percent of what you make, you’ll [have] over $1,000,000 by the time you’re 65,” O’Leary previously told CNBC Make It.

As Warren Buffet describes it (using the explanation favored by his right-hand man, Charlie Munger): It’s like “being at the top of a very large hill with wet snow and starting with a snowball and getting it rolling downhill.”

Many, from Cuban to Buffett, suggest index funds are a good place to start.

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Disclosure: CNBC owns the exclusive off-network cable rights to “Shark Tank.

Disclosure: NBCUniversal is the parent company of NBC and CNBC.