Forbes recently released its list of the 400 richest Americans. This year, the list is particularly notable, because you had to be at least a billionaire to be included.

As you might expect, a significant number of the folks on the list made their fortunes by investing. That subset includes Warren Buffett (worth $46 billion), Carl Icahn (worth $9.7 billion), and Jim Simons (worth $4 billion).

So here's important lesson No. 1: You can make a lot of money if you learn to manage your portfolio like a pro.

Easier said than done ...
Of course, that collection of billionaire investors offers no clue regarding what strategy is most likely to make you a billionaire. Warren Buffett is a dyed-in-the-wool value investor. That strategy has helped him achieve annual returns greater than 20% at Berkshire Hathaway for more than 40 years, on the back of investments in boring companies such as GEICO and Washington Post. That investment tack continues in his portfolio today, with USG (NYSE:USG), American Standard (NYSE:ASD), and M&T Bank (NYSE:MTB) among the company's current holdings.

Jim Simons, though, can point to 34% annualized returns at his Medallion fund since 1982, net of what are believed to be some incredibly stiff fees. He favors a mechanical strategy, based on computer models that are constantly refined by an army of Ph.D.s.

So while there is no best strategy, important lesson No. 2 is obvious: You gotta dance with the one that brung ya.

Say what?
Colloquialisms aside, all of these investors are astoundingly successful because they've figured out how they make money best, stuck with their strategy in good times and bad, and refined their best practices over time.

Buffett was mocked during the technology bubble, when companies that he avoided and professed not to understand as well as others, such as Amazon.com (NASDAQ:AMZN) and Hewlett-Packard (NYSE:HPQ), were zooming to the moon. But they've come back to earth, and Buffett's still doing just fine today.

Icahn has a reputation as a corporate raider; he's made a lot of money instituting changes at underperforming companies. Although Icahn's recent efforts at Time Warner haven't been as successful as past efforts, Icahn has said he'll be patient. After all, he's worth nearly $10 billion. Why mess with success?

And Jim Simons doesn't try to analyze businesses as Buffett does, because that's not where his expertise lies.

Mimic the masters
The secret to successful investing, then, is not found in any single strategy, but rather in picking the strategy that's right for you and executing it faithfully. As lauded NYU finance professor Aswath Damodaran writes in his book Investment Fables, "Each strategy has the potential for success if it matches your risk preferences and time horizon and if you are careful about how you use it."

That's it. That's the secret. Because if you get too cute -- chasing hot sectors, buying high and selling low, and giving yourself only six months or less to master a given investment strategy -- you're simply setting yourself up for failure.

Allow me to introduce ... myself
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This article was originally published on Sept. 30, 2006, as "Join the Billionaire Boys Club." It has been updated.

Tim Hanson does not own shares of any company mentioned. Berkshire Hathaway is an Inside Value choice. Time Warner and Amazon are Stock Advisor choices. The Fool'sdisclosure policyassures you that no stocks were harmed in the writing of this article.