This article was updated on April 30, 2015.

Millions of Americans know they haven't saved enough for retirement, but they think they don't have the time to research investments in order to reach their goals of retiring rich. Yet there are simple and effective ways to invest for long-term needs like retirement expenses, so you needn't let fear or inexperience hold you back from achieving success with your investment portfolio.

In the following video, Motley Fool investment planning editor Lauren Kuczala talks with longtime Fool contributor and financial planner Dan Caplinger about two simple ways to save for retirement. One offers automatic adjustments to your investment mix over time, while the other allows you to customize your portfolio to your specific needs with a wide variety of investments at your disposal. Both methods help you get on track to meet whatever financial goals you set for yourself in saving for retirement or other long-term needs. Dan discusses how you can choose between these two great alternatives to create a retirement portfolio that matches your investing philosophy.

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.