Need that money for retirement in the next couple years? Don't put it in a hot emerging-markets fund.
Consider when you'll need access to your money. This will help you avoid unnecessary transaction fees, penalties and risk.
For some goals, such as paying for college, it may make sense to use a mix of investments, says Gail MarksJarvis, author of "Saving for Retirement (Without Living Like a Pauper or Winning the Lottery)."
"If you are saving for college and your child is within three years of going to college, you've still got seven years until that last year of college," she says.
So while the bulk of short-term college savings should probably be very safe in CDs or short-term bonds or a high-yielding savings account, maybe some of that money could be invested in stocks. "Just remember the rule of thumb," she says, "that money you'll need within five years shouldn't be in stocks."