At times like these, when the markets are extraordinarily volatile, a financial advisor's most effective marketing tool may be somewhat of a surprise.

My conversations with advisors this summer always seemed to drift to: What's working? And most of the responses were some version of the same theme: Stay in touch with clients; ask for referrals; attend seminars; cross-sell; and so on. But perhaps the best idea, shared by the most successful advisors, was quite simple: Remain fully invested in a basically conservative, diversified portfolio.

First, understand that this is not a marketing strategy that can be turned on and off with market swings. It has to be the basis of a practice. That said, advisors who adhere to it report few, if any, client defections, a minimal need for handholding and a continued flow of new money to invest regardless of the Dow's direction. They also report a steady stream of income for assets under their management.

They advocate remaining fully invested at all times, except for having enough cash to carry the client for a predetermined period. That automatically eliminates any attempts to time the market (and the related commissions), not to mention having to sell at bottoms. "My clients have to agree up front that we will remain in the market no matter what," explains one advisor. "My approach is to tell them that by selling in down markets they will not only spend assets on commissions, but they will be losing dividends while they are out of the market."

The concept is simple. Develop relatively conservative, diversified portfolios—primarily by using mutual funds and managed money. That immediately removes any risk of the advisor recommending individual securities that may fail. Those who use this approach explain that the portion of a client's portfolio that is conservative may vary based on the client's age, objective and total assets. But every portfolio has a conservative asset base.

The advisors who use this long-term investing approach also say that they only recommend mutual fund families and asset managers, which means they're offering their clients the added benefit of diversification. "I can't preach enough about the value of diversification," says one advisor. "I make sure I send every client at least one or two letters a year on the benefits of diversification, even those who have been in my program for years. It never hurts to reinforce a solid investment concept."

Finally, nearly all these advisors also say they periodically remind clients to add to their portfolios as they accumulate cash. This can be through an automatic dividend reinvestment program or by adding new money. "When we keep the cash flowing into an account, we create an automatic dollar-cost-averaging scenario for the client," one advisor says. "I always explain how that works at one of our first meetings, so it becomes part of the basis for our account management."

"This program makes it easy on me in all markets," another advisor says. "My clients don't panic in down markets and can sit back and relax in up markets.... I began getting referral after referral, particularly after my clients successfully weathered downturns."

This marketing strategy is not only the basis for managing a practice, but for building long-term trust and confidence with clients. And while it takes time to implement this approach, the coming new year may be the time to begin, particularly with new clients. For existing clients, you could suggest this strategy in their first review of 2009 and perhaps protect them from the anguish of a down market the next time the Dow heads south.

Larry Silver, director of marketing at Raymond James Financial until his retirement, writes about investment firm practices from Oldsmar, Fla. He can be reached at lsilvermarketing@yahoo.com.