►In your 30s
Start now. The sooner you begin, the less money you have to part with. To retire on 80 percent of a $40,000 income, a 30-year-old has to save 10 percent of her salary; a 40-year-old has to put away 15 percent to build the same nest egg.
Stock up. Invest mostly in stocks. Even if the market suffers 10 bad years, your account will have time to recover. Keep it simple with a low-cost index fund. The Fidelity Select Software and Comp fund, for example, has yielded, on average, more than 11 percent a year since 1996.
►In your 40s
Put yourself first. Don’t sell out your future for your kids’ education costs. They can borrow money, but you can’t take out a loan for your golden years. Plus, you might be able to use IRA proceeds to pay for college.
Get advice from a pro. This is the time to sit down with a planner to devise goals for your future and learn how to save, spend and invest to reach them.
►In your 50s
Stay in to win. Although you should ramp up your percentage of savings in bonds, don’t shift out of stocks entirely. To outpace inflation, you still need to lean on their higher growth potential.
Catch up on savings. The IRS lets you put an extra $5,500 per year, tax-deferred, in 401(k)s plus another $1,000 in your IRA. Doing so lowers your tax bill and lets you add more to your investments if you got a late start.