3. A college education

College doesn't always pay off financially. In the U.S., one out of five men and one of seven women who have college degrees earn less than their counterparts with just a high school diploma. The worst off are the ones who take on huge amounts of debt and either never get their degrees or get degrees in fields with poor job prospects.

But for the vast majority of college graduates, a degree makes a huge difference. Their median household income was $78,200, while households headed by those with only a high school diploma earned $36,700. The Pew Research Center estimates that, after factoring in the costs of college and earnings forgone during those years, the typical college graduate earns $550,000 more than the typical high school graduate over a lifetime.

Household wealth for U.S. college graduates is significantly higher, as well.

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Furthermore, unemployment rates for college graduates are half of what they are for people with only high school diplomas.

The takeaway: A college degree is important. It will become more so in the future as well-paying manufacturing and union jobs disappear. But it matters what you study and how much you pay for that education. College students and their families need to make sure they're studying for fields that have good job opportunities. Plus, they have to make sure they don't overdose on loans. Read "Should your kid skip college?" for more.

4. Self-employment

You've heard scary statistics about how many small businesses fail -- statistics that are usually exaggerated, by the way.

Create the right business, though, and the upside is all yours. The self-employed not only earn more (their household median income was $75,700 in 2007, compared with $56,600 for employees), but they accumulate dramatically more. The median household net worth of entrepreneurs was $388,700, compared with $93,200 for households whose head worked for somebody else.

But what about that high failure rate? You may have heard that anywhere from half to 90% of small businesses fail in the first year, but that isn't supported by research. When a small business employs at least one person besides the owner, 70% survive at least two years, half are still around five years later and a quarter stay in business 15 years or more, according to the Small Business Administration. And the "dropouts" aren't necessarily failures. Businesses can be shut down or sold for a number of reasons, including a serial entrepreneur who's moving on to something else.

Annually, about 10% of employer businesses close for various reasons. The turnover rate for owner-only businesses is harder to track, but the SBA estimates it's about three times higher since it's easier to open and shut a shop when you don't have employees.

Now consider the "failure" rate when you're working for others. Even among older, more stable workers -- those aged 39 to 44 -- one-third of the jobs they got ended in less than a year, and 68% ended in less than five years, according to a study by the Bureau of Labor Statistics.

The takeaway: Entrepreneurship, like marriage or homeownership, isn't for everyone. But if you have a desire to run your own show, you shouldn't let other people's failures hold you back. You can find plenty of free and low-cost help in starting a business from the SBA, including the small-business development centers located in many cities, and from SCORE, a nonprofit educational group that connects small-business owners with experienced mentors.

5. Choosing to save

Are you convinced the reason you can't save is that you don't make enough money? You're probably deluding yourself.

Income differences don't explain why some households accumulate wealth and some don't. Ivy League researchers Steven F. Venti and David A. Wise found that some high-income people wind up with little wealth and that some low-income people accumulate a lot.

A study of 3,992 households whose heads were near retirement age found income differences explained just 5% of the variations in wealth. Life events such as inheritances, big medical bills, divorce and the number of children accounted for just 4%. Investment choices accounted for 8%.

So what made the most difference? How much the households chose to save. Even some of the lowest-income households managed to accumulate significant wealth.

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The takeaway. Making savings a priority, and paying yourself first from every check you get, turns out to be the No. 1 way to build wealth. So get started. For more, read Trent Hamm's wonderful post "12 excuses for being broke."

Liz Weston is the Web's most-read personal-finance writer. She is the author of several books, most recently "The 10 Commandments of Money: Survive and Thrive in the New Economy" (find it on Bing). Weston's award-winning columns appear every Monday and Thursday, exclusively on MSN Money. Join the conversation and send in your financial questions on Liz Weston's Facebook fan page.