Contribute to a retirement account
If your employer offers a 401(k) or a similar plan and matches contributions, be sure to contribute up to the full employee match. Otherwise, you're leaving money on the table, Millstone says.
For most young people, a Roth IRA or Roth 401(k) makes the most sense for retirement savings because the money will never be taxed again after being placed in the account.
"Even if you don't have a company-sponsored retirement account, you can open your own IRA," Millstone says.
"One key element to the equation in retirement savings is how you allocate your investments," Sweeney says. "You need to assume some risk and exposure to stocks in order to grow your savings. For young people, 90 percent of their money should be in stocks, but when you're closer to 65, you should allocate more of your money to fixed-income investments."