How prepared are you for retirement? This is National Save for Retirement Week and a good time to examine personal retirement planning.

A while back, TD Ameritrade surveyed baby boomers on retirement readiness, and its conclusions shed some light on what it really takes to retire comfortably. The survey found that among the 71% of boomers who believe they are prepared to retire -- or are already retired comfortably -- 74% are married and 75% no longer have children who live at home. About 84% started saving for retirement by the time they were age 30. Overall, they describe themselves as self-motivated, optimistic, decisive overachievers who are inclined to handle their money conservatively, even when times are good.

Of these boomers who consider themselves well prepared for retirement, 18% say they require a retirement income of more than $100,000 a year. The majority of those not yet retired say they could live comfortably on less than $100,000 (the median income requirement is $82,500). For many people, achieving this level of retirement income demands hefty savings, with 16% saying they'll need $1 million and 4% saying they'll require more than $3 million. Most of the rest say they don't know how much they'll need.

While Social Security plays a role in almost everyone's retirement, among boomers who are already retired and feeling well prepared, 53% say they could lose Social Security and still live comfortably.

How did those who feel secure reach that comfortable spot? There is no magic in their answers:

   Managed their money using little or no credit - 67%.
   Saved early and often - 58%.
   Spent sparingly on luxuries - 58%.
   Landed a job with a good salary - 56%.
   Invested savings in a well-balanced portfolio - 51%.

Preparing for a secure retirement isn't easy, but this survey suggests you don't have to be Warren Buffett to do it. You do have to be smart enough to manage your money well.