You may be hesitant to discuss the potential breakup of your business partnership, fearing that such talk could prove self-fulfilling. But clarifying sticky questions while your partners are on good terms can help prevent some of the tension that leads to business divorce. And if you do decide to split, written agreements can assure that everyone's treated fairly.

"There's an assumption by many partners that even if their businesses fail, they'll be partners forever," says attorney David Gibbs, of Boston's Peabody & Brown. He advises clients to set up an agreement detailing how they'd establish the worth of company stock if one partner wanted out, what each would do if a partner should die, and how to govern the sale of stock to outsiders. For small companies, most such agreements cost between $1,000 and $4,000.

And there's a side benefit, says Gibbs. Partners who can't come to terms on how they'd get out of their relationship might want to rethink getting into one.