For most of us, the biggest portion of our nest egg comes from the money we have socked away in our employer-sponsored retirement plan. But not enough people take maximum advantage of their plans. And even those who do might not be putting money to work in other investments that provide the same tax-favored earnings growth.

But some folks out there -- perhaps even the coworker in the cubicle next to you -- know exactly what it takes to get the job done.

Want the inside scoop? Here's a start.

Take the money and run
If your company matches retirement-plan contributions up to a certain level, make sure to kick in at least as much as your employer will match.

Even if your company's plan isn't the world's greatest, it's hard to beat doubling your money while reducing your taxable income. And the deal is even sweeter if you're among those lucky workers whose plan offers an impressive lineup of mutual funds. But what exactly constitutes an impressive mutual fund? There are three key things to look for:

  1. A low fee
  2. Experienced, winning management
  3. Intelligent diversification

Keeping those elements in mind, your plan should feature an anchor fund that specializes in stalwarts such as Citigroup (NYSE:C), Disney (NYSE:DIS), and Time Warner (NYSE:TWX) -- a power trio of dividend-paying companies with attractive prices. It should also provide a fund whose managers look toward growth-oriented fare such as Activision (NASDAQ:ATVI) and Marvell Technology Group (NASDAQ:MRVL) -- stocks with high earnings-growth estimates over the next five years. First Marblehead (NYSE:FMD) is a similarly dynamic contender for such funds.

The bottom line? If your retirement plan keeps a lid on costs and provides investments that you can spread across the market's valuation spectrum, give your administrator props: You've been handed a smart way to build a diversified portfolio.

Take it to the limit
Another smart way for retirement-minded workers (i.e., all of us) to proceed is with a Roth IRA. Provided you don't exceed the income limits, you can contribute to a Roth in addition to the moola you plunk down in your 401(k). Unlike a traditional IRA, you won't be investing pre-tax dollars. The trade-off, though, comes later: When you pass the 59-and-a-half-year mark, you're free to tap those proceeds without paying Uncle Sam a single cent in taxes.

When it comes to preparing for your financial future, a Roth is another deal that's tough to beat.

Stay informed
If you want to retire in style while meeting important near-term goals, like buying a house or funding your child's college education, it pays to stay up to speed on your options for getting those jobs done. Even investing newbies should strive to stay abreast of the available strategies. To help you do just that, the Fool introduced its Motley Fool Green Light service last year.

In the just-released October newsletter, our ongoing Portfolio Boot Camp series teaches you how to add growth to your investments, including our take on a handful of top growth stocks and mutual funds. We also appeal to your contemplative side, exploring what affects your financial satisfaction (or lack thereof). You can check it all out for free with a 30-day guest pass. Click here to get started.

This is adapted from a Shannon Zimmerman article originally published on Dec. 7, 2006. It has been updated.

Allyson Cohen does not own shares of any company mentioned above. Disney, Time Warner, and Activision are Stock Advisor recommendations. First Marblehead is a Hidden Gems and Inside Value pick. You can check out the Fool's strict disclosure policy by clicking right here.