NEW YORK ( MainStreet) — So-called "lifestyle investing" has been around Wall Street for decades.

That's where Americans invest and save for certain periods of their lives, such as getting their first job and paying off student loans, getting married, buying their first home or saving for their kids' college years and their own retirements.

In essence, Wall Street-types refer to this kind of saving and investing program as a "live document" that can take a life of its own and needs to be managed more closely as big life events near.

The best move you can make with lifestyle retirement plans is to pay strict attention. The worst move? Ignoring your savings and taking your investment for granted.

"Lifetime retirement investing has never been more important.," says Nick Ventura, president and CEO of Ventura Wealth Management , a Ewing Township, N.J.-based financial planning firm.

"A financial plan should be a live document, where individuals and families measure progress towards their goals," he says. "Many people put their retirement plan and their retirement account on the shelves and don't evaluate them for years."

This "set it and let it" philosophy could have seriously bad consequences, Ventura says. "In today's constantly shifting economic landscape, it's critical for the plan and for portfolio asset allocation to adjust to help prevent insurmountable losses and meet retirement objectives."

Ventura says Americans steering toward big financial mileposts — and their retirements — should build a lifelong financial planning strategy that covers all the bases.

Here's his guide to getting that job done from your 20s on up:

In your 20s: The younger you are, the more you should take whatever help you can, Ventura says. "Take advantage of employer-sponsored retirement plans, especially those which offer a match, and begin to build an emergency fund" of three to six months of living expenses, he says. "Additional preparatory steps include assessing debt and evaluating life insurance, especially if they have a mortgage and/or a child."

Entering your 30s: Broaden your financial horizons as you grow older. "Maximize 401(k) plans, but make investments outside of employer plans as well," he says. "Reviewing credit scores during this stage of life is crucial, and certain credit situations, such as opening and maxing out retail credit cards, can heavily impact credit during this stage." In addition, Americans in this phase should build worth within their homes and begin to review estate documents in addition to life insurance policies — that's an extremely important step to take for those with children, Ventura says.

In your 40s and beyond: Once you pass 40, retirement savings takes center stage. "At this stage, adults really begin to think of retirement planning in its reality," he says. "Be strategic, make smart career moves and consolidate retirement accounts from previous employers."