Financial success can be due to making good decisions or avoiding big mistakes. In many cases, the biggest mistakes happen after good decisions, because the stakes have become higher.

As an example, let's consider the dilemma of Motley Fool reader Jim, who emailed us this question: "Did I make a substantial error when taking money out of my IRA?"

To help answer that question, Jim sent along some details:

Whether you can retire, and whether your money will last after you retire, starts with a very simple maxim: spend less than you have. However, once you start actually crunching some numbers, you find that the equation of retirement is actually quite complicated, with many variables that have different consequences. And that's a good thing, because it gives you options -- different levers you can pull to shore up your retirement security.

What are those levers, and which will have the biggest impact on your retirement? As with many things regarding financial planning, the answers depend partially on your unique circumstances. However, in this article we'll discuss the factors common to most retiree-wannabes, and quantify their results for two hypothetical workers - one 35-year-old and one 50-year-old -- using the "Am I saving enough? What can I change?" calculator found on Fool.com. That calculator produces results in terms of the number of months your retirement will be fully funded. As the tool estimates the impact each variable has on our test subjects, we will report the results in terms of additional years of a fully funded retirement, just so you don't have to divide the results by 12 in your head (not that we don't trust your math skills -- we just think it makes more sense to think in terms of years).

And now, let's lay out the starting point for each of our guinea pigs, whom we'll call Fergie and Madonna.

Hiring a financial advisor is difficult. Common questions include: How much do financial advisors make? How much of that is my hard-earned money? What's a reasonable fee?

Way back in the '90s -- a primitive time when a mobile phone could only be used to talk to another phone -- I was a broker (i.e., salesman) with Prudential Securities.

Note: Robert's post is particularly timely this week, which is National Financial Planning Week. Time to get your finances in order!

Let's get this out of the way up front: This post is going to be a downer. So — right now — I want you to think of something happy to do after you've read it.

Got it? Good. Because this article is all about risk — in other words, all the things that can go wrong with your financial plan. We'll talk about ways to mitigate these risks, but thinking through this stuff isn't going to be all rainbows and cupcakes (though we've attempted to lighten things up with photos from the hilarious website AwkwardFamilyPhotos.com). Still, it's better to know what's possible and take preemptive action rather than stick your head in the sand, especially because getting sand out of all your head holes can be very difficult. So let's take a deep breath and confront the potential grim side of reality.

"Work, work, work, work, work, work. Retire."

That's how New York University professor Sewin Chan described the traditional retirement path at a symposium several years ago. However, that path may be changing. Her research indicates that approximately one-third of retirees from 1992 to 2004 reversed their retirement. Today, the path might look more like this (as Chan illustrated in her PowerPoint presentation): "Work, work, work. Retire (for a bit). Work. Retire?"

I re-discovered these little quotes by reading through past issues of my newsletter, which is about planning for — and living in — retirement. However, as I've written before, I'm a retirement expert who doesn't plan on retiring. I'm not sure it's best for most people's health or wealth. And it might be just too dang risky. Plus, I like what I do, where I do it, and the people I do it with. Of course, I still save for retirement because who knows if I'll feel the same way 30 years from now.

Yes, this is another article bemoaning the cost of a college degree, and the amount of student debt that many graduates take with them alongside their diplomas -- assuming they graduate, which doesn't always happen. (Paying off students loans without a college degree must be the epitome of rock-and-hard-place-ishness.)

You've read all the numbers about how the cost of college has risen far faster than the median household income, and how there's now more student loan debt than credit card debt. But besides the fact that debt stinks, graduating with a $30,000 I.O.U. (or more) has plenty of other harmful effects:

Student loans bring future consumption to the present. Debtors (often being paid entry-level salaries) have to devote a portion of their income to what they would otherwise be spending on cars, homes, kids, and iThingamajigs (well, they'll still buy those last things, but put it on the credit card, which is just more future consumption being spent now, with interest). This drains money from the overall economy, benefitting no one but the universities and the student-loan providers.

Longtime readers may remember a few things about me:

• At various times, I've studied to be a priest, a doctor, a teacher, and a financial advisor (though I was only two of those).
• My posts can get so technical (okay, boring) that J.D. has to enliven them with cat pictures.
• I've tried to lose weight over the past couple of years, and have concluded that reducing heft is very similar to building wealth.

Regarding the latter, I reported in January that I was down about 25 pounds in 18 months. Not bad — at least good enough to get me on public radio's Marketplace (in case you're dying to hear my nasally voice). Managing your cash and managing your flesh both start with giving up short-term pleasure for long-term gain.

This occurred to me again as I met earlier this summer with Ben Sterling, my office's resident Wellness Fool. His scale told us that I had gained back almost seven of the pounds I had lost. I had still been exercising, but not as much and not as intensely, and I didn't pay any attention to what I ate. Ben, in his wisdom, knew he had to give me more motivation — and given my financial background, he knew that motivator was money (though for me it's the preservation of it, not the making gobs of it). So we made a bet: I would lose six percentage points of body fat by mid-September or I'd pay him $200 (which would go toward buying exercise equipment for the Fool office).

When it comes to investing, you have two big decisions to make: What to buy, and where to buy it. As for the former, you have all kinds of choices: cash, bonds, stocks, funds, real estate, and a piece of carpet from Elvis' jungle room (yes, I have a piece — at least, that's what the guy who sold it to me said it was). Regarding the latter, most people have just three general options: a traditional retirement account, a Roth retirement account, and a regular investment account. This article is about the second category — how to make the most of your investment accounts.

Stop the Sprawl

If you're like many investors, you have accounts spread throughout the financial services industry: an IRA or two here, a brokerage account there, perhaps a 401(k) still with a former employer. If you're married, your spouse probably has a lineup to match. By consolidating as many of those accounts as you can with a single provider, you'll unclog your mailbox and make tax time easier -- and you can even make your portfolio fatter, thanks to these advantages:

• Find a better balance. Determining your asset allocation can be tough when you have to look at lots of statements. Rebalancing across several accounts gets tricky; for example, you can't sell the bonds in your 401(k) to buy stocks in your IRA.
• Move money out of mediocre (or worse) accounts. This is especially true of money left in retirement plans from former employers, which often have limited investment choices at high costs.
• Get extra services and discounts. Financial companies lure big accounts with lower fees, plus planning services such as a portfolio analysis or access to a Certified Financial Planner.

Find the Best Provider

Choosing a company that deserves the honor of holding your nest egg depends on your style of investing. Here are guidelines based on your investments of choice:

We at The Motley Fool have always been champions of the individual investor, encouraging each person to take control of her or his financial destiny. In theory, the transition of America's retirement apparatus from defined-benefit plans — i.e., pensions that pay a monthly amount — to defined-contribution plans — such as 401(k)s and 403(b)s — is consistent with this Foolish philosophy. The individual makes all the contribution, investment, distribution, and inheritance decisions, whereas with a defined-benefit pension, the worker has very little control.

However, for the majority of Americans, the transition away from defined-benefit has not been to their benefit. It requires each person to become an investing expert and financial planner in their spare time, and too many Americans don't seem to have the time, interest, inclination, or skills.

According to the Employee Benefit Research Institute, the average 401(k) account is a tad over $60,000; those within a decade of retirement have a bit more, with an average balance of $78,000, but more than a third have less than $25,000. Almost half of workers (43%) between the ages of 45 and 54 reported they weren't saving anything for retirement.

One of my jobs at The Motley Fool is to serve as the internal financial planner for Fool employees. Lately, however, I've been answering more questions my colleagues have about their parents — and it's more likely about their mothers or mothers-in-law. The truth is, women face a more difficult task when it comes to retirement planning, for several reasons:

Women earn, and have, less. According to the Census Bureau, women earn just 77% of what men make. They are also more likely to interrupt their careers to raise children or take care of older relatives. According to the Social Security Administration, the typical woman spends 12 years out of the workforce. This results in lower retirement benefits and smaller portfolios. On average, a female's 401(k) is 40% less than a male's.

Women live longer. Generally, retirement begins when a person leaves the workplace and ends when life leaves the person. The longer someone lives, the longer retirement lasts — and the more assets will be needed. On average, gals live five years longer than guys, which means they tend to be retired longer. Add to this the fact that, with most couples, the wife is a few years younger than the husband, and you can see why most women should plan on spending their last few years on their own. Which leads us to…