Last year's Pension Protection Act continued the high contribution levels allowed in tax-advantaged accounts, such as 401(k)s and IRAs. So you can stash away a maximum of $15,500 in your 401(k) this year. (For regulatory reasons, your plan may set lower limits.) And most employers make matching contributions, typically 50% of up to 6% of salary. That's free money you shouldn't pass up.

You can also save as much as $4,000 in an IRA. And if you are 50 or older, you can make catch-up contributions as well - this year an additional $1,000 in an IRA and another $5,000 in your 401(k).

Even if you do all that, you may not come close to having as much as you need.

So to avoid spending your golden years in Junior's guest bedroom, you'll have to put money in taxable accounts too.

Choose tax-efficient investments, such as index funds or tax-managed funds, whose buy-and-hold strategies minimize short-term capital gains and interest income.

To come up with those extra savings, you'll have to liberate more cash from expenditures. You can start gradually, by resolving to live on less, say, for a three-month trial. Perhaps you can hold off on a new car for a few more years and vacation in St. Paul instead of St. Martin.

Either you learn to embrace the rather unappealing idea that you must curb your spending, or you can have money automatically withdrawn from your pay and plunked in savings before you ever see it.

"People usually find that they adjust their spending to the cash flow they have," says Adam. "The inconveniences are outweighed by how good you feel that you are on track to a secure retirement."