While getting a great return on your investments pumps up your portfolio, the biggest determinant of your net worth -- at least when you're starting out -- is how much you can invest. After all, even earning market-beating returns won't do much if your investment is worth just a few hundred bucks.

Searching for the highest returns is a noble pursuit (many of us Fools live for it, in fact). However, many people would be better off focusing their energies on something more predictable than the stock market: their savings rate. Of course, to save more means to spend less. That's not always easy, but we can help.

Today, we'd like to introduce you (or perhaps reintroduce you) to the concept of living below your means (LBYM). This is a manner of living in which you make a concerted effort to save money and spend carefully.

Why should you bother? Because, Fool, your retirement will need to be financed somehow, unless you intend to work until you're 90. Don't you want to be lounging around by the pool reading trashy novels in a big floppy hat when you're 70?

At Fool.com we have an entire discussion board dedicated to sharing ideas and advice on the best methods to live below your means. This is the Foolish Mecca for all things fiscally responsible and frugal. Below are a few of the most popular tips gleaned from the board:

  • Start by trying to get a handle on your spending. Carry around a small notebook and write down all of your expenditures for a month. Only when you fully understand where all of your money is going can you begin to efficiently spot places to cut back.

  • One of the most repeated tips on the board involves eating out: Don't do it! Or at least, don't do it as often as you probably have been. Cooking at home can save you tons of money. Along that same vein, take your lunch to work instead of heading to McDonald's (NYSE:MCD) every day. And drink more water -- it's cheaper and healthier than soft drinks. You'll be shocked at how much you aren't spending just by following these few suggestions.

  • Keep up the maintenance on your car. Make sure that the brakes work and that the oil's been changed before you hear that grinding noise or smell smoke and have to pay for a major repair.

  • Shop at garage sales and thrift stores. You know that old saying about one person's trash being another person's treasure? There's a great deal of truth in that.

  • When and where you can, buy the generic version of foods at the grocery store. Think about buying in bulk, too, from a warehouse club.

  • Make a wish list for items that you'd like to buy. Implement a "waiting period" for your wish list, and honestly examine your "wants" vs. your "needs." Don't buy anything from your list until the waiting period's up.

  • Don't buy on credit unless you're prepared to pay off your balance every month. Interest charges can make even the most frugal purchase's price skyrocket.

  • Can you bank cheaper? How about your insurance? Get new quotes to see if you can get your current coverage for less. Is your phone service the cheapest possible? Do you really need super-duper unleaded gas for your car? Would the quality of your life be greatly affected if you no longer had your current cable TV package -- or cable at all? What about that cell phone? Look carefully at every category in your budget and ask yourself how you can do it for less.

  • Quit smoking, Fools! Save your money and your life!

There are tons more tips on the Living Below Your Means discussion board. Click on in and share your ideas. Then, once you start accumulating extra savings, put it to work. Visit our Savings Center and Discount Broker Center for ideas on how to best use your newfound cash.