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.

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," .

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."

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