The toys of the wealthy -- wine collections, jewelry, fine arts, racehorses and the like -- are often dangerously underinsured.

"I had a client who had a (Frederic) Remington painting," Clement says. "I had previously dealt with a Remington and knew their value. When I looked at the client's policy, their Remington was insured for $400,000. Sounds like a big number, right? It was worth $4 million."

Homeowners policies may cover fire damage and theft, but their loss limits typically fall far short of that range, include a deductible and don't cover accidental damage, "mysterious disappearances" or holdings in multiple locations. That can leave the toys at your beach house or ski chalet completely exposed.

High-net-worth policies remedy those shortcomings. "Fine-arts coverage is all-risk worldwide with no deductible, so if they have it in multiple homes, in the office or on loan to a museum, it's fully covered," says Clement. Better still, there's coverage during transit and shipping, where most fine-arts losses occur.

"We recommend a policy upgrade every three years and sometimes sooner if the artist has passed away because then the art appreciates pretty fast," she adds.