But other parts of the world are tightening their tax policies too. Britain recently overhauled its tax system to impose a charge on wealthy foreigners who live there but are nondomiciled for tax purposes. That may result in a migration of people to the U.S., enlarging demand for pre- and post-immigration planning.

"It's now becoming an international play," Meola says. "In New York, people come for five to six years to work and accumulate wealth. They have tax issues."

Eden sees a strong trend in teaching the responsibilities of wealth to the next generation, especially entrepreneurs. Many of them were so busy making money they didn't have the time to stop and enjoy the philanthropic activities they employ to preserve it.

"It's a tough topic to broach, to explain to the next generation how much money they have, let alone how to deal with it," Eden says. "People are increasingly concerned about being set apart as different, that their kids enjoy life for themselves, feel self-sufficient, live in their own reality. Replace a group of trustees with family members and you're excited about getting everybody to work together."

Estate-tax savings can run from 15 to 45 percent, with a median 30 percent, advisers say. The trick, according to tax attorney Steven H. Seel, a partner at Thorp Reed & Armstrong L.L.P. in Pittsburgh, is to create a plan that provides for participation as well as gifting when the time is right.

Many of his clients own closely held businesses. To deal with estate-tax issues, they're putting properties in partnerships and trusts to move assets down to the children.

Never put all the beneficiaries' inheritance in the partnership, Seel warns. With $20 million, for example, put half in the partnership, half in cash. That may form more solidarity among siblings. And avoid a backlash at the parent's death from an unhappy sibling or, worse, his dissenting spouse.

When it comes to philanthropy—the most favored destination for tax savings—charitable-remainder trusts, charitable-income trusts, donor-advised funds, and, especially, foundations all get high marks.

Meola notes that clients are seeking to maximize retirement plans to preserve money—cash benefit plans and defined benefit plans—especially for small businesses. One client is looking to buy a series of hotels through a retirement plan in a five- to seven-year turnaround, all tax-free.

"Do these people need their retirement plans? No," Meola says. "If you hit a grand slam, that's great. The trade-off is that it all comes out of ordinary income. The buildup down the road is so substantial. You take out a minimum distribution and pass it down to your heirs."

Real estate still has a strong draw. Investing in historic preservation enables the investor to write off depreciation and interest expense and receive historic-preservation tax credits on a dollar-for-dollar basis of up to 20 percent. Historic buildings are less vulnerable to the vicissitudes of the real estate market. "As we're watching the real estate market tank, you're looking at an asset that's not going to disappear," Eden says.

Moreover, good-value real estate is hard to find, especially in the Northeast, Meola says. "We're almost at the point of saturation, and urban sprawl is not weighing favorably for the developer," he says. 

There may be value in brownfield sites—abandoned or underutilized commercial and industrial properties with some environmental contamination. "Brownfield sites are on the comeback trail," says Meola, whose office is on an old brownfield site. "It's an opportunity if you have enough wherewithal and guts and money."

"Our clients are getting excited about investing again," Eden says of real estate. "They're not ready to pull the trigger today, but they're getting ready to put the pieces together for the intermediate term."