These days, success isn't just about working hard. It's more about working hard and efficiently. So why not apply that strategy to your investments?

To measure a company's efficiency, you can examine its return on equity (ROE): its profit margin, multiplied by its asset turnover, further multiplied by its financial leverage. ROE measures how efficiently the company employs its owners' capital -- your bang per buck as an investor. Take Colgate-Palmolive (NYSE: CL) or Altria (NYSE: MO) both of which boast ROEs of 70% or more. That's a lot of concentrated bang.

Companies can juice their ROE by employing more debt, so it's important to consider a company's debt level when looking at ROE. All things being equal, though, the higher the ROE, the better: A higher ROE means a more efficient company, which in turn means a more effective executive team managing the business. You should consider companies like these for your portfolio.

To uncover some of the most efficient companies around, I ran a screen using The Motley Fool's CAPS screening tool. I looked for companies with:

• CAPS ratings of four and the maximum five stars. The high ratings indicate the companies are more likely to outperform the market.
• ROEs of 25% or greater.
• Market caps of $500 million or greater, to keep us out of microcap land.

Here are seven companies that I like:

Data from Motley Fool CAPS. TTM = trailing 12 months.

While the stock screener is a great tool, it should be only the first step in your research. Examining other levers of specific companies, such as return on invested capital, liquidity, and debt-to-equity ratios, will also help you determine if a company is right for your portfolio. When you include those other metrics in your analysis, you'll get a fuller picture of whether that company is worth buying.

Start increasing the efficiency of your investments at Motley Fool CAPS today. Let the collective wisdom of our 165,000-member-strong community help you make better investing decisions. It's free.

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