Like many affluent baby boomers, Paul Schervish and his wife worry about the impact of their wealth on their children. So, instead of leaving the three kids a lump-sum inheritance, they’ve structured a trust that will distribute its holdings “like a good parent,” providing support for home buying, education, and health care.

As director of Boston College’s Center on Wealth and Philanthropy, Schervish knows he’s hardly alone in his concerns. As families participate in the biggest wealth transfer in history, estimated at more than $45 trillion, “they’re trying to figure out how to make inheritances productive, not destructive,” Schervish says.

That often means employing one or more trusts. Though frequently touted for their tax benefits, trusts can also help preserve and protect wealth and enable parents to exert control over children’s lifestyles. The irrevocable nature of most trusts can provide substantial protection from divorcing spouses, medical malpractice judgments, and other claims by creditors.

Trusts are almost infinitely flexible. “You can write just about any trust provision you want, and some people set very specific requirements that have to be met before payouts are made—that a child attend a particular college, say, and receive a set grade point average,” says Jeffrey Condon, co-author with his father Gerald Condon of Beyond the Grave: The Right Way and the Wrong Way of Leaving Money to Your Children (and Others).

Getting that specific is usually a mistake, says Condon, though he does encourage clients to consider establishing solid criteria for how beneficiaries—a spouse, children, grandchildren, or even those in succeeding generations—gain access to trust assets. Condon believes such restrictions are preferable to the common practice of simply staggering payouts—for example, giving beneficiaries a third of their share at age 30, another at 35, and the rest at 40. “Heirs can blow those installments just like any other windfall,” he says.

To help protect a “problem” child, who may have a drug or alcohol habit, a trust could put a great deal of control in the hands of a professional trustee, such as a bank or trust company, that will not only oversee trust investments but also cut the checks for all beneficiary expenses. Sometimes, trust provisions also call for a third party, a family friend or relative, to help assess an heir’s needs and keep the professional trustee informed.

But Condon warns against a “carrot and stick” approach that imposes too many conditions. “No matter how well such trusts are drafted, everyone may wind up in court, with the kid saying he or she has met the conditions and the trustee saying the heir hasn’t.” A better solution, in such cases, Condon says, is simply to limit the payout. “That way, the heir knows this is all that’s coming. Sometimes, the best you can do is hope your children’s lives will be happy. Trusts can do many things, but they can’t force your children to live the way you want when you’re no longer around.”