Are you sitting down? I'm about to reveal the great secret of wealth, the closely guarded hidden method used by the greatest wealth builders of all time. This is the one true path to riches, the age-old mystic secret passed down through the most successful families of all time and shared in whispers with the most fortunate among us.

Are you ready? Here it is:

Spend less than you earn.

I know, you've heard it before. It's the core message of countless personal finance texts, starting with the classic The Richest Man In Babylon. Some of the wealthiest people in America call that book a key to their success. As it turns out, it's a pretty simple book. If you haven't read it, here's the essence: invest 10% of what you earn, make wise spending choices with the remainder, avoid excessive debt, and you'll eventually be wealthy, even if your earnings seem modest at the beginning. It seems obvious, doesn't it? Even if you earn a million dollars a year, you're not going to become wealthy unless you're investing some of that -- spending less than you earn. It's just common sense.

Yet the savings rate in the U.S. is lower than it has been in decades. Clearly this sense is not as common as it should be. What to do?

Avoiding the "B" word
Those same countless personal finance texts will tell you to start by making a budget. Personally, I hate the word "budget." It's up there with "frugal" and "self-deprivation," carrying a flavor of pinched, slightly shabby, totally demotivating un-fun-ness. We're going to need to stay motivated in order to get wealthy. So instead of a budget, let's have a plan. Better yet, a secret plan. A Secret Wealth-Building Plan, for secret wealth-building agents! Here are the elements of our plan:

  • Self-surveillance. Watch your spending for a month. Sit down every night and try to record every dollar you spent over the course of the day. You can use a notebook or a software application like Quicken. Either way, stick with it for a month. For many people, this will be a stunning, eye-opening experience.
  • Intelligence assessment. Just the act of keeping the log will help you become conscious of your spending habits, and you'll probably find yourself spending less. Start asking yourself if you really needed that green couch, or if it was just a momentary spending impulse triggered by something else. As you ask yourself these questions, you'll start getting a grip on your impulse spending. But remember that it's still OK to splurge -- as long as you can really afford it without adding to debt or impinging on other goals, and as long as the purchase seems genuinely worthwhile to you.
  • Debt extermination. Once you have your impulse spending under control, you'll have some extra cash. Start by using it to pay off those credit cards and any other high interest debt. Need help getting started? Look here.
  • Strategic reallocation. Once you've nuked the high-interest debt, it's time to start investing. Are you contributing enough to your 401(k) to collect all of your employer's match? If so, set up an IRA. Already contributing the maximum to your IRA? Max out that 401(k), or consider setting up a regular brokerage account. Whatever you do, you want at least a few months' salary put away in a "rainy day" fund. That fund doesn't have to be a bank account, but it should be invested in something that isn't too volatile -- at least until your base of non-retirement savings is big enough to get through a market storm while still leaving you enough to cover several months' worth of expenses.
  • Advanced intelligence. It's not enough just to invest. You need to be smart about your investments. For most of us, that means buying stocks. The Richest Man in Babylon tells us to seek the counsel of the wise, but I suggest you seek the counsel of the Foolish instead. If you're new to picking stocks, or don't have the time or inclination to do the necessary research, might I suggest that you try the Motley Fool Stock Advisor service? Every month, founding Fools David and Tom Gardner present their two best stock ideas, the end results of hundred of hours of research, supported by easy-to-understand explanations and a special members-only discussion board for your questions and comments. Their past picks have included such great finds as Omniture (NASDAQ:OMTR), Hasbro (NYSE:HAS), and BorgWarner (NYSE:BWA), all of which have doubled (or more) since they were first presented to Stock Advisor members. Check it out -- you can have full access with no obligation for 30 days.

And remember, it's a secret! Shhhh!

Fool contributor John Rosevear thanks his twin seven-year-old sons for reminding him that everything is more fun when there's a SECRET PLAN involved. Omniture, Hasbro, and BorgWarner are Stock Advisor recommendations. The Motley Fool's disclosure policy gave up smoking years ago, but still loves Aston Martins, dry martinis, and playing chemin de fer at the Casino in Monte Carlo.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.