Managing a Stock Market Slump

4. Rebalance your portfolio. Add up your portfolio at the end of the week and see how you stand versus your plan. If you wanted to have 60 percent of your money in stocks and you now have 55 percent, add more stocks. It'll be hard, but had you done this rebalancing regularly during the financial crisis of 2008 and 2009, you'd have gone into the most recent downturn with more money than you had even at the peak in 2007. This is your chance to get it right this time.

5. Add another 1 percent to the contribution rate to your 401(k). If the market is going to rebound, you're boosting your contribution at just the right time. If not, well, you're going to need the extra savings anyhow.

6. Note to workers: Send your boss some chocolates or tickets to the home team's baseball games. If you're lucky enough to have a job, you'll get through this fine; if the market disappoints for the rest of your career, well, you can work longer. When you have a job, you have that option. It sure beats the cardboard box.

Also of interest: 5 retirement planning mistakes.

Eric Schurenberg is the financial editor at large for AARP The Magazine and a former managing editor of Money magazine.