NEW YORK (CNN/Money) - With the major stock indexes up sharply since the start of March, it's only natural to want in on the goods -- especially if you've been hoarding cash.

But while it's certainly a good time to be in stocks, it's not necessarily the right time to throw yourself headlong into them with every available dollar, said certified financial planners Doug Flynn and David Caruso.

Here's why.

Say you developed an acute case of risk aversion when the bear market kicked into high gear. You chose to squirrel away a larger-than-usual portion of your money in bond, money market and stable value funds. Even though you know it's better to sell high and buy low, chances are you ended up selling at least some of your stocks at or near their lows in order to preserve what was left of your money.

That behavior suggests you may not have such an appetite for stocks. If you didn't want to buy when the Dow closed below 7,300 back in October 2002 -- indeed, if the stock market's lows were incentives to sell -- "you have to exercise a lot of caution buying now," Flynn advised.

This latest rally has been like a small scoop of Haagen Dazs after years on a fat-free diet. But "you'll need the numbers in the earnings for this rally to be justified," Flynn said, adding that some of the run-up can be attributed to pent-up demand. "People are looking for good news. When they see it, they'll act on it."

Even if the rally is the beginning of a long-term upward trend in the market, as Flynn thinks it may be, that doesn't mean stocks can't maroon investors from time to time in a ditch, whether because of poor economic numbers, corporate malfeasance or geopolitical turmoil.

The question is how much of your money do you want exposed to those dips? Flynn suggests asking yourself this: Would you feel worse if you didn't get in at Dow 9,000 and it climbed to 10,000, or if you got in at Dow 9,000 and it fell to 7,500?

None of this is to say you shouldn't increase your allocation in stocks, especially if you're way off from your target asset allocation.

But both Flynn and Caruso think you shouldn't do so all at once, with high percentages of your overall portfolio.

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The first step is to assess your asset allocation. Say you originally planned to have 60 percent of your money in stocks and 40 percent in fixed income and cash. It's likely that breakdown has shifted to 50-50 or 40-60, stocks to bonds.

"Now is a very good time to do the rebalancing game," Caruso said. In helping clients with this exercise, he advises, "Let's go where we're not."

In other words, use the gains in your portfolio or some of your cash on the sidelines to correct the balance in your investments.

Beyond rebalancing between stocks and bonds, Caruso recommends taking a hard look at your large-cap growth and value stocks. "If you have a lot of value, I think it's a good time to get into growth," he said.

That's because growth stocks were far more beaten down that their value counterparts during the bear market. As such Caruso is overweighting his clients in that area.

But for investors jonesing for the halcyon days on the Nasdaq, he cautions them to cap their tech stock allocation at no more than 20 percent of the stock portion of their portfolio. For those who need reminding, he recounts how after rising more than 80 percent in 1999, the Nasdaq went on to erase all those gains and then some between 2000 and 2002.

For the large-cap value portion of a client's portfolio, he currently likes the dogs of the Dow -- the 10 stocks in the Dow Jones that finish the calendar year with the highest dividend yields. They may not be the best performers long-term, he said, but they'll get a lot of investors where they need to go, with an average dividend yield of 4.2 percent.

"It's like owning a nice piece of real estate," Caruso explained. "You know it won't go bankrupt and you get a nice cash flow."