We've all heard the old investing adage "buy low, sell high" -- which is sound (if obvious) advice. But as commonsensical as that particular truism seems, following it can sometimes be downright painful. Some stocks never look "low," after all, and passing them up because their multiples seem rich can take a toll on your portfolio.

For example ...
Consider the cases of Apple (NASDAQ:AAPL) and Schlumberger (NYSE:SLB). These go-getters sport five-year earnings-growth estimates of at least 15% and trailing-12-month price-to-earnings (P/E) ratios that clock in above that of the S&P 500. Starbucks (NASDAQ:SBUX) and Yahoo! (NASDAQ:YHOO) also fit that bill, and all have beaten the S&P 500 for the 10 years that ended with April, too.

Highfliers, of course, can sometimes take you for a wild ride on the road to investment riches. All of the above have certainly experienced performance gyrations, which prompts this question: If you're the kind of investor who wants the gain but prefers to keep the potential pain to a minimum -- and aren't we all? -- what's the best way to proceed with apparently pricey growth stocks?

Two words: mutual funds. All the stocks mentioned appear in the lineup of one of my favorite mutual funds, a pick that's risen nearly 50% since I first recommended it to members of the Fool's Champion Funds investing service. Because those names appear in a well-diversified portfolio that recently included buttoned-down big boys like Hewlett-Packard (NYSE:HPQ), Home Depot (NYSE:HD), and Wal-Mart (NYSE:WMT), investors here have been treated to a relatively smooth ride, too.

To wit: Despite the fund's focus on growth stocks, it has been only slightly more volatile than the broad-market-tracking SPDRs (SPY) exchange-traded fund (ETF) for the five years that ended with March. Over that same period, moreover, our Champ has struck a slightly milder profile than its typical Morningstar peer -- all while pole-vaulting over 90% of its like-minded competitors.

The Foolish bottom line
If you're looking to wade into the potentially choppy waters of growth-stock investing, good for you: With greater risk comes the potential for greater reward. That said, I think you'd be Foolishly wise to consider getting the job done with a well-chosen mutual fund, a pick that provides plenty of bang for your growth-investing buck, and the peaceful, easy feeling that comes with owning a stake in a well-diversified portfolio.

If you'd like to sneak a peek at all the funds I've recommended since Champion Funds first opened for business -- a group that has bested the market by more than 13 percentage points to date -- just click here and snag a free 30-day guest pass. There's no obligation to stick around if you find it's not your cup of tea, so go ahead and give the service a whirl.

Take Champion Funds for a test drive now and you'll also have access to our latest special reports: The Challenge: ETFs vs. Mutual Funds and Add Kick to Your 401(k)! Just click here to get the reports along with your free 30-day guest pass.

This article was originally published on Oct. 10, 2006. It has been updated.

Shannon Zimmerman runs point on the Fool's Champion Funds newsletter service, and at the time of publication, he didn't own any of the securities mentioned above. Starbucks and Yahoo! are Motley Fool Stock Advisor recommendations. Home Depot and Wal-Mart are Inside Value picks. You can check out the Fool's strict disclosure policy by clicking right here.