Baby-Sitter

Your kids are reciting lines from Pulp Fiction over a 9 P.M. dinner of Krispy Kremes. Every night.
Also works for: Nannies, day-care providers, music teachers, coaches.

Passive
Fib and fictionalize. Rather than say, "We can't afford child care anymore" (which works only if the sitter won't ever run into her replacement), rely on realistic but mild reasons for letting her go: "We really need someone who cooks/drives/isn't scared of our Chihuahuas." If she's a full-time nanny, soften the blow by giving her a cushion of money to fall back on. The standard is one week's pay for each year of employment.

Aggressive
Sack her in the heat of the moment. Often it's one relatively minor event in a string of events that finally breaks you. (Although you may regret your overblown reaction, you probably won't regret firing her.) But "if you suspect abuse or neglect, drop the sitter immediately. No question about it," says Zuzana Andreanska, owner of a nanny management consulting business in Connecticut.

Preferred
"Most of the time, the sitter isn't dangerous — it's because the relationship isn't working," says Andreanska. This makes the conversation even more difficult, because your kids may have grown attached to her and she to them. Let her go in private with a kind word ("It's just not the right fit, but I think you are great"), then give her a chance to say good-bye to your kids before she leaves.