For most people, simple low-fee index funds are enough. They will accept your regular infusions of cash and deliver growth at roughly the same rate as the index they track (for example, the S&P 500). Over two or three decades, that can help you amass a sizable nest egg for retirement.

If you want to aim for faster growth, consider adding some growth stocks to your mix. Here are several great investors' bits of advice to help you zero in on great growth stocks -- and invest in them effectively.

A close-up picture of Warren Buffett smiling.

Warren Buffett is one of the most successful investors ever. Image source: The Motley Fool.

What Peter Lynch recommends

Not everyone knows Peter Lynch's name these days, but they did a few decades ago. Peter Lynch was the manager of Fidelity Investment's famous Magellan mutual fund from 1977 to 1990, and he averaged an annual return of 29% during that period. He has written several classic books on investing that are well worth reading.

In his book Beating the Street, Lynch said, "This is one of the keys to successful investing: focus on the companies, not on the stocks." If you ever find yourself considering various stocks for berths in your portfolio while solely looking at a few stock-related metrics for them -- such as their price-to-earnings (P/E) ratios or how much they've risen or fallen in value lately -- beware.

As Lynch noted in One Up On Wall Street, "Know what you own, and know why you own it." Ideally, you'll have studied each stock you have considered or purchased until you had a good grasp of what it does and exactly how it makes its money. You can't just say McDonald's, for example, sells fast food. Its business model is actually focused on franchising its restaurant and leasing real estate to franchisors. Lynch has also said, "If you can't explain to an 11-year-old in 2 minutes or less, why you own the stock, you shouldn't own it."

What Phil Fisher recommends

First published in 1958, Philip Fisher's Common Stock, Uncommon Profits and Other Writings is another investing classic. It includes 15 things to look for when you're searching for great investments. He explains how to find growth stocks, too.

Among other things, Fisher favors companies offering products or services that have great growth potential for at least a few years, strong profit margins, effective research and development efforts, and managers who have a long-term outlook, aiming to continue offering new products to keep growing the company.

Fisher has noted that, "The stock market is filled with individuals who know the price of everything but the value of nothing." This means that focusing on a stock's price is far less valuable than focusing on the business of the company -- what it seems to be worth now and what it's likely to be worth in the future.

What Warren Buffett recommends

Then there's Warren Buffett, who needs little introduction, having grown his company's (Berkshire Hathaway) value by an annual average of around 20% over more than 50 years. Buffett has offered myriad bits of guidance about how to invest well.

One of Buffett's key tenets is staying within his "circle of competence." In other words, don't buy into stocks and industries you don't understand well. You need to have a good grasp of their business, their strengths and risks, and their competitive landscape. While biotechnology stocks may entice, for example, understand that paint companies and waste collection companies and farm supply retailers can also be rapid growers.

Buffett has also noted that, "It's far better to buy a wonderful company at a fair price than a fair company at a wonderful price." In other words, do pay attention to the price of a stock, but don't aim to buy whatever seems cheapest. Many of the best companies rarely sell at very low prices -- though these days, with the market down so much, there are plenty of seemingly undervalued growth stocks.

If it's starting to seem like it might be a lot of work to study companies to find the most promising ones, that's true. So consider another bit of Buffett advice: Simple invest for the long haul in low-fee index funds. Remember that many great growth stocks will be in broad-market indexes such as the S&P 500, so index funds will let you benefit from their growth.

However you go about investing, whether in index funds, growth stocks, or a combination of approaches, be sure that you are investing for your future. Learning more about the investors above can help improve your results, too.