Though fortunes have been diminished these past few volatile weeks, the world’s roster of billionaires has a significant number of folks who made their fortunes by investing. That subset includes Warren Buffett, Carl Icahn, and Jim Simons.

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, Washington Post (NYSE:WPO), Johnson & Johnson (NYSE:JNJ), and Wells Fargo (NYSE:WFC).

Jim Simons, though, can reportedly point to 30%-plus annualized returns at his Medallion fund since 1982, net of what are believed to be some incredibly stiff fees -- and his is 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, what's made all of these investors astoundingly successful is that 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 Intel (NASDAQ:INTC), 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 -- as he tried to do at Biogen Idec (NASDAQ:BIIB), and as he successfully did in ImClone's (NASDAQ:IMCL) $70-per-share sale to Eli Lilly (NYSE:LLY).

And Jim Simons doesn't try to analyze businesses like 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 only giving yourself six months or less to master a given investment strategy -- you're simply setting yourself up for failure.

Allow me to introduce ... myself
Of course, if you're looking for the right investing strategy for you, allow me to suggest our approach at Motley Fool Hidden Gems. There, we use bottom-up fundamental research to identify small companies that we believe will beat the market over time.

We also advocate broad diversification, a buy-to-hold mentality, minimizing taxes and transaction costs, and adding savings to your portfolio on a regular basis. Taken together, we think this strategy will help you achieve your financial goals. If that catches your fancy, you can be my guest at Hidden Gems free for 30 days. Just click here for more information.

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

Tim Hanson owns shares of Berkshire Hathaway. The Motley Fool also owns shares of Berkshire. Intel and Berkshire Hathaway are Inside Value choices. Berkshire and Biogen are Stock Advisor recommendations. Johnson & Johnson and Eli Lilly are Income Investor picks. The Fool's disclosure policy assures you that no stocks were harmed in the writing of this article.