Rising health-care and food costs and a slowing economy have hit many Americans in their debit cards -- and their retirement plans. The Employee Benefit Research Institute's annual survey reports that just 18% of workers and 29% of retirees are "very confident" they'll have the resources for a comfortable retirement -- the lowest levels in seven years.

I asked a panel of Fool advisors and analysts for their thoughts on this turn of events.

1. According to the 2008 Retirement Confidence Survey, our collective confidence in our ability to afford a nice retirement is at its lowest level in seven years. Seven years ago, we were also experiencing a significant market downturn. How can we maintain confidence in our retirement plans in bull markets and bear markets?

Robert Brokamp, Motley Fool Rule Your Retirement advisor: You build a portfolio that will withstand both bull and bear markets by owning assets that don't all move in the same direction at the same time.

Seven years ago, while U.S. large caps were sucking wind, real estate investment trusts (REITs) and bonds were up. In 2002, when the S&P 500 was down more than 22%, Duke Realty (NYSE: DRE) was up 13%, and Simon Property (NYSE: SPG) was up 24%.

Dayana Yochim, Motley Fool consumer finance expert: As much as I'd like to offer uplifting, keep-your-chin-up words of wisdom to everyone wrangling with retirement planning issues, I think everyone will be better served by the truth (sweetened with a dose of "rah-rah"). Here's the deal: There's only so much in life that you can control. However (this is the rah-rah part, by the way), there's so much in life that you can control.

When times are tough, it's easy to forget who's really in charge. (If it's not perfectly clear by now, here's the answer: You.) You have control over how much of your portfolio is invested in stocks, bonds, funds, and CDs. You decide whether you're more comfortable moving your money to safer havens, or whether you have the stomach to stick it out. You are in charge of the very actions that will make the biggest difference to your present and future quality of life.

When panic and uncertainty start to creep back into consciousness and the Dow, the FTSE, Ben Bernanke, and Simon Cowell start to act up, there's still just one person who controls how it all plays out on your turf. Yup, that's your cue.

Bill Barker, Hidden Gems Pay Dirt senior analyst: As with so many other things, I think Shakespeare said it best in Hamlet: "There is nothing either good or bad, but thinking makes it so." And it's always worth keeping that in mind, particularly when you see market fluctuations. Lower prices in the market mean it's a good time for buyers -- a bad time for sellers. No more, no less.

When it comes to retirement, we spend -- or should spend -- a far greater percentage of our lives preparing for it and saving for it than actually in it. So you're hoping for periods like this, where your 401(k) and IRA contributions buy more stock for the same dollar than they did at the same time last year. Twenty, 30, 40 years from now when you retire, you'll be happy for the times the market was down, and you were still putting some savings in the market.

Toward the top of the market in the late 1960s was not the best time to be buying the "Nifty Fifty," -- companies you'd want to hold for decades, such as Coca-Cola (NYSE: KO), Anheuser-Busch (NYSE: BUD), IBM (NYSE: IBM), or McDonald's (NYSE: MCD). These same companies were little changed, but their stocks were at half the price in the mid-1970s, and they were great retirement investments at that point.

2. The Retirement Confidence Survey repeatedly finds that calculating retirement needs is associated with increased saving for retirement, but any calculation of retirement needs is only as good as its assumptions. What are the biggest mistakes people make in calculating their retirement needs?

Brokamp: The biggest mistake is relying on just one calculator. Each one has its strengths and weaknesses, so your best bet is to use three to five and take an average of the results. A good calculator takes into account all the important variables: taxes, inflation, pensions, the different characteristics of traditional retirement accounts and Roth accounts, and lump-sum investments later in life.

The Rule Your Retirement service includes a higher-powered financial-planning tool that can handle all these variables, plus the information is saved so you don't have to input everything all over again when you want to run a checkup on your plan.

Yochim: I know exactly how Robert will respond to this question, because I have taken this particular piece of his advice to heart for many years: When you sit down to calculate your retirement needs, pretend you're Goldilocks -- consult at least three calculators and run at least three scenarios through each. That way you'll be able to catch any anomalies that one calculator might miss.

Also, the results are also only as good as the inputs you provide. If, for example, you don't know what it costs to cover your living expenses today -- your housing, transportation, food, clothing -- the calculations about your future costs are going to be as flawed as your inputs. Ballparking is fine to get started. But when it's time to crunch the real numbers for your future, shoot for accuracy.

3. When confidence about retirement plans is at a low point, as it is now, workers report planning to push their retirements later so they can save and compound for a few extra years. Retirees, on the other hand, report having retired earlier than they had planned. How can we plan for conditions like this that are outside our control?

Brokamp: Use conservative assumptions when you analyze your retirement plan. Assume that stocks will return less than the historical 10% annual average, that you won't get all you're projected to receive from Social Security, and that you'll retire a few years sooner than you're currently planning. This will build a margin of safety into your plan.

Yochim: "Control is just an illusion." That's what a professional horse trainer said as I gracelessly hoisted myself into the saddle of what I just then realized was a 1,000-pound mode of transport with a mind of its own. Comforting, I know.

Still, that less-than-confidence-boosting counsel is worth remembering whether you're a city slicker or an individual investor: Hold on! Over the short term the market is going to do its thing -- go up, down, in circles, and all sorts of directions. But give it time, stay in the seat, and history shows that its general trend is in one direction: up. Because of that, the market has always rewarded plain-old patience.

If you tend toward queasiness, your best bet is a diversified portfolio with a bunch of investments that don't always move in the same direction. And, finally, when you feel the urge to dump every stock you own and hide all your money in your mattress, consider the findings of Wharton Business School professor Jeremy Siegel, who found that from 1871 to 2006, stocks outperformed bonds in 82% of 10-year periods, 96% of 20-year periods, and 100% of 30-year periods.

Barker: Above all, start saving early. There's no substitute for it in terms of the rewards you'll have in retirement -- whenever that may be. Savings that have compounded for decades will give you a lot more latitude to time your retirement than hasty attempts at playing catch-up later on in life. Also, putting money aside early conditions you to more disciplined spending throughout your life -- something you'll absolutely have to have in retirement.

4. Only 72% of workers have saved for retirement, and 49% report savings of less than $50,000, not counting their primary residence. What can Americans do to help improve these statistics?

Brokamp: People need to realize that contributing to retirement accounts has big tax advantages. If you contribute to a traditional 401(k) and are in the 25% tax bracket, you'll cut your taxes by $250 for every $1,000 you contribute to the plan. You won't pay taxes on the investment gains until you make withdrawals in retirement.

Yochim: Given those statistics, I'd say that the answer is "anything." Or even just "something." Seriously, you don't need to do an extreme retirement makeover to improve your lot. Just do one thing -- like save 3% more than you did last year -- and you'll move the needle in the right direction and start a positive trend for your future.

So if you sock away an additional $1,500 (3% of a $50,000 salary) this year, and you earn an 8% average annual return over five years, you'll add $735 to your earnings. Not bad. If you commit to the 3% goal for five years (for a total of an additional $7,500 invested), your retirement nest egg will blossom by more than $11,000 if you had done nothing at all.

Barker: The easiest thing to do is simply to enroll in your company's 401(k) plan and contribute at least the amount needed to get the full employer matching contribution, assuming there is one. Also, find any nifty online retirement planning calculator and run some numbers. You'll quickly see that you need to save a lot more than $50,000 to have any kind of comfortable retirement -- unless you're counting on Social Security suddenly tripling its payouts.

Also, to move that needle up to and past $50,000, use no-load index funds -- from companies like Vanguard or TIAA-CREF -- or exchange-traded funds like SPDRs (AMEX: SPY) or Vanguard Total Stock Market. If you're going to invest through managed mutual funds, never buy something sold by a broker.

For more tips on securing your golden years, test-drive our Rule Your Retirement service free for 30 days. You'll get access to specific stock and fund ideas, robust calculators, model portfolios and asset-allocation models, and advice on retirement accounts. Click here to get started.

Julie Clarenbach does not own shares of any company mentioned. Robert Brokamp, Dayana Yochim, and Bill Barker don't, either. Duke Realty is a Motley Fool Income Investor recommendation. Coca-Cola and Anheuser-Busch are Inside Value choices. The Motley Fool owns shares of SPDRs. The Motley Fool's disclosure policy is invested for life.