I turned 35 recently. It wasn't very long ago that 35 seemed like a relatively old age. But I'm not old, right?

Then I look around at my life and notice that I have a daughter who recently turned 2, a hairline that has turned my forehead into a fivehead, and -- most damning of all! -- a minivan. So perhaps it's time for me to start investing like an adult.

I don't have 760 months until retirement
For my daughter's portfolio, I prefer a high-growth investing style with the assumption that if one of four fliers turns into Genentech or Microsoft sometime in the next couple of decades, she'll be filthy rich. If three of the companies go bankrupt along the way, well, live and learn. That's what a long time horizon and a high tolerance for risk will do for you.

But for me, now that I've hit the randomly magical milestone of 35, that might not make quite as much sense, especially if I hope to retire before my daughter gets married -- and since she's not allowed to date until she's 30, that's a way off.

No, for my portfolio, value investing seems to make better fiscal sense, at least for a large chunk of my investments. Maybe it's the specter of middle age looming, but I don't feel like I can afford to swing and miss as much anymore. It's a little sad to hear myself talking so practically, but it makes sense to buy solid, stolid companies that might not wow me with 40% growth estimates by breathless analysts but will assuredly rise in value over time.

Looking over the scorecard of our Motley Fool Inside Value newsletter is hardly as breathtaking as a glance at the Rule Breakers list of recommendations. It's a list of banks and consumer goods conglomerates and companies that make Post-it Notes -- things that everyone already knows everything about -- not mysterious biotechnology companies that might someday develop a winning drug.

The obvious can help you
Bill Mann is one of the smartest analysts here at Fool HQ. He wrote in a recent column that obvious facts cannot help you profit in the stock market. Rather, the key is to find companies that have growth potential that others don't realize.

That's helped Bill in his own small-cap crusade, but when it comes to large caps, I think the obvious can help you a lot.

3M is an excellent example. The company has a $50 billion market cap, 100 years of innovation under its belt, and, as anyone who watches his company's office supplies arrive knows, very little chance for abject collapse. Plus, the company does well by its shareholders. As Philip Durell wrote in his formal recommendation of the company in the September issue of Inside Value:

3M recently boosted its quarterly dividend from $0.36 to $0.42 a share (up 16.7%), so the stock yields approximately 2.3% going forward. In the past year, the company has repurchased a net 1.35% of shares outstanding, which in my book is another way of returning value to shareholders. Put those percentages together, and 3M yields more than 3% to shareholders. The company is also able to internally fund capital expenditures and its very necessary R&D programs. Over and above this capital allocation, the company has increased its cash hoard from $302 million at the end of 2000 to $2.67 billion at the end of March 2005.

Thrilling? Perhaps not. Smart? Yup. And the stock is down slightly since Philip recommended it, presenting an even better buying opportunity. Slowly, surely, 3M is positioned to reward long-term investors. And I promise 3M isn't going out of business anytime soon.

Value all around
Moreover, if you take a look at stocks within 5% of their 52-week lows, it's almost a who's who of excellent businesses: White Mountains Insurance (NYSE:WTM), Kohl's (NYSE:KSS), Pitney Bowes (NYSE:PBI), Cendant (NYSE:CD), Church & Dwight (NYSE:CHD), Smucker (NYSE:SJM), and E.W. Scripps (NYSE:SSP), among others. Some of these companies have short-term risk -- White Mountains is being hit hard by the high cost of the recent hurricane season and Cendant lowered earnings guidance -- but none of these companies carries nearly the risk of that pharmaceutical company waiting on positive phase 2 data that could give my daughter a 20-bagger.

This, of course, doesn't mean that I've become a man with a short timeline or total risk aversion. I still (hopefully) have many investing years ahead of me, but it's time I changed my focus. I'm not as eager to chase those high-risk, high-reward fliers with a chance at excellence. I need to focus instead on proven businesses that generate cash, pay dividends, and offer compelling long-term growth prospects -- not because of an innovation that might pay off but because the market is selling them at a discount. That's profit with a side of capital preservation. And with a young family and savings accounts for college and retirement piling up, I'm beginning to really respect Warren Buffett's two rules of investing. Rule No. 1: Never lose money. Rule No. 2: Never forget rule No. 1.

Foolish final thoughts
Every month, Philip offers up two new picks that he's confident will increase in value over time. Thus far, his track record is impressive: In the first year and a half of the service, Philip's Inside Value picks are besting the S&P 500 by three percentage points. If you sign up for a free, no-obligation trial today, you'll have immediate access to all active recommendations as well as all of the research behind them.

When looking to get rich slowly, it's best to invest like an adult.

This article was originally published on Oct. 12, 2005. It has been updated.

Roger Friedman is the managing editor of newsletters and the author of Nipple Confusion, Uncoordinated Pooping and Spittle: The Life of a Newborn's Father . He does not own shares of any company mentioned in this article. Pitney Bowes is a Motley Fool Income Investor recommendation, and Cendant is an Inside Value selection. The Motley Fool isinvestors writing for investors.