It’s only common sense — the sooner you begin saving for retirement, and the more you save for it, the better off you’re going to be.

But not everyone has the discipline to begin socking away retirement savings early on, much less even think about a retirement plan before turning 40, even though most experts agree that doing so is the most expedient way to a financially secure future.

Surveys suggest that most people 55 and older didn’t begin saving seriously for retirement until age 42. But there are ways for pre-retirees to catch up, says personal finance writer Lynn O’Shaughnessy, who covers that and myriad other financial planning strategies for retirees in her book “Retirement Bible” (Hungry Minds Inc.). Also, she says, never have consumers had so many tools and resources, many available online, to use to create retirement nest eggs and make the most of them later on.

For those who need to get in the retirement-savings game late in the game, O’Shaughnessy says that one of the most important things you can do is to make sure you are getting the most return for the least cost when it comes to retirement investments, such as Individual Retirement Accounts or 401(k) plans. Many consumers don’t realize that most mutual funds cost investors money, as do 401(k) plans, and this can add up to significantly lower returns, O’Shaughnessy says.

“One thing people can actually control is expenses,” she says, “You need to pay close attention to what you’re paying for mutual funds.”

As an example, O’Shaughnessy used a mutual fund cost calculator on the Security and Exchange Commission’s Web site, www.sec.gov, to compare two $49,000 nest eggs in two funds, one with an expense ratio of 0.18 percent and the other with a 1.4 percent ratio. After 25 years and estimating a 10 percent return, the first fund would be worth $507,000 with $23,381 in fees and foregone earnings. The second fund would be worth $373,195 with $157,705 in fees and foregone earnings. Since all mutual funds must list their expense ratios, it’s simple to compare, O’Shaughnessy says. Most top performing funds, she notes, have some of the lowest expense ratios.

Other tips O’Shaughnessy offers for catching up on retirement savings include:

Postpone retiring or work part time. Not only will it increase your Social Security benefits, but you also can funnel more of your paycheck into the company savings plan. The amount you will get from your pension, if you have a defined benefit plan, also will increase. If you think there’s a chance you might have to go back to work after retiring, don’t quit now; in most cases, salaries are much lower the second time around.

Pump up contributions to tax-deferred accounts. New IRA rules give pre-retirees leeway to put thousands of additional dollars into 401(k) plans. In addition, start a Roth IRA and put the maximum in that per year as well.

Make savings your life. Time really is money at this stage of the game, O’Shaughnessy says. If you’re 40 and start putting $100 a week into a stock mutual fund that earns 11 percent a year (the overall earnings of stocks over time), you’ll have $367,455 in 25 years before taxes. If you wait until you’re 50, you’d have to invest $260 a week to reach the same amount.

Factor retirement consequences into any job move. You may want to consult a financial planner to compare retirement benefits of any new job you’re considering and to calculate any losses you might incur leaving your current retirement plan.

Cash in your home equity. If your house has appreciated in value, and you don’t need the space, sell it and buy a cheaper house, and invest any capital gains you have left. Couples can pocket $500,000 in capital gains tax-free.

Talk to an expert, but the right expert.

“Remember,” O’Shaughnessy says, “Stockbrokers are sales people not financial planners.”

She recommends talking to a certified financial planner or a certified public account with retirement planning expertise to help sort through the complexities of long-term retirement planning. To find such experts, contact the National Association of Personal Financial Advisors (888) 333-6659 or www.napfa.org or the Financial Planning Association (800) 282-6526 or www.fpanet.org.