The stock market crash following the Internet bubble destroyed portfolios and dreams. The Nasdaq alone fell from 5,000 to below 1,200 -- a nearly 80% decline. And that's only the average. Many stocks became essentially worthless. The tragedy wasn't in the numbers, though -- it was the effects on people. A significant number of investors were completely wiped out, losing money that they'd been saving for years.

It's bad enough hearing the stories. This really isn't the sort of pain you want to experience firsthand. That's why it makes sense for all investors, at all times, to have a portfolio that is prepared for lean times. If a terrible day ever comes, you'll want to make sure you suffer only a flesh wound, not total decapitation.

At Motley Fool Inside Value, we specialize in identifying stocks that not only outperform on the upside but can also survive a crash relatively unscathed.

Diversify, now
Investors with technology-focused portfolios suffered the most a few years ago. There was almost nowhere in the sector to hide, with even the strongest companies suffering huge declines. Microsoft (NASDAQ:MSFT) fell 50%, Cisco (NASDAQ:CSCO) fell 75%, and Yahoo! (NASDAQ:YHOO) fell 90%. Even now, none of these companies is even close to its pre-bubble highs. And these are some of the top performers in the sector.

The moral of the story isn't that technology companies are risky, but rather that diversification is a key component of a crash-resistant portfolio. While tech has been dreadful, the Vanguard REIT Index has more than doubled since 2000, and energy stocks have had outstanding returns recently. A diversified portfolio that included technology, REITs, and oil would have prospered. Furthermore, diversification ensures that you get the full benefit of your stock selection skills. The crash has shown that it's no condolence identifying the best-performing stocks in the worst-performing sector. Being the best of the losers doesn't make you a winner. But if you pick the best of each sector, you'll do quite well.

The Inside Value newsletter follows this diversification philosophy by recommending stocks in sectors ranging from technology to financial and with market caps from $2 billion to $200 billion. Even our selection strategies vary -- we'll search for everything from undervalued growth stocks to cheap businesses poised for a rebound after suffering downturns or temporary bad news.

Buy cash
The problem with the companies that fell the most when the bubble burst was that they had neat ideas, but didn't actually make any money. Even some of the largest, most prestigious companies had this problem, such as Nortel Networks (NYSE:NT). For years before the crash, Nortel hadn't made a cent, but investors assumed that since the top line was growing and networking was huge, Nortel would be a great investment. It was a costly mistake.

Unprofitable companies have little flexibility in bad business climates, and tend to do poorly in bear markets. In a panic, investors aren't buying dreams. They're sticking with consistent cash machines like PepsiCo (NYSE:PEP) and Target (NYSE:TGT). It's no coincidence that these two companies show spectacular long-term returns, unfazed by the recent bear market. Businesses that earn gobs of cash don't have to raise money in order to survive and can even take advantage of poor conditions to gain market share from weaker competitors. Such businesses tend to be crash-resistant.

At Inside Value, every single pick is a real business that makes piles of cash and has a huge competitive advantage. Consequently, these companies position themselves well in case of a bear market or a worst-case-scenario market crash.

Be skeptical
One of the best ways to guard your portfolio against a market crash is by maintaining healthy skepticism. Wall Street isn't a charity. It's a bunch of businesses focused on making money for themselves. Helping small investors make a profit is Item No. 382 on the list of Wall Street priorities, immediately after ensuring that the new assistant knows exactly the right amount of Splenda to put in the morning coffee.

Be skeptical of analyst forecasts, whether it's a prediction that oil will hit $110, or that Ariba (NASDAQ:ARBA) will break $500. While Ariba's insane price targets were trumpeted on TV before the crash, I haven't seen many apologies for the stock's subsequent performance.

Instead, rather than trusting the analysts, make sure that you understand the companies you're buying. Understand what risks face each business and what competitive advantages will help the company to overcome hurdles. Be particularly wary of high growth estimates, because analysts tend to be optimistic and high growth is difficult to sustain. If the company fails to achieve overly ambitious growth estimates, the stock will be beaten down. Finally, only buy a stock if, after conservative analysis, the company is trading at a bargain price. Stocks tend to return to their intrinsic value, so buying below that value provides significant protection in a crash.

We follow these techniques at Inside Value by performing our own research, starting with a thorough understanding of the company. As part of each recommendation, we not only describe what the company does, we also discuss the competitive landscape and possible risks. Finally, we only recommend stocks that are trading at dirt cheap prices. On average, our picks last year were recommended at prices equal to 72% of their intrinsic value. There is some variance. At the time of publication, one pick was trading at only 53% of its intrinsic value.

So while a crash will have some negative effect on any portfolio, a few carefully chosen strategies -- such as those used by the Inside Value team -- can help you avoid the worst and give you the opportunity for big gains along the way. If you're interested in reading our recommendations, we offer a free, no-risk 30-day trial. A trial gives you access to current and past issues of Inside Value, a discounted cash flow calculator for calculating the intrinsic value of any stock, dedicated discussion boards, and two special Inside Value reports. There is no obligation to subscribe.

Richard Gibbons is scared of stock market crashes, large flying objects, and eerie music. He owns call options on Cisco, but does not have a position in any of the other companies mentioned in this article. The Motley Fool has a disclosure policy.