A cheat sheet on tipping do's and don'ts

The size of a restaurant gratuity depends on how well you are served, including whether your order is correct or if your server checks on you after you receive your food, says Hoffman. Don't base your tip on the food's taste; the server has no control over it.

Hoffman's tipping guidelines:

• Restaurant wait staff: 13 percent to 20 percent of the bill.

When your party stays through the time that the restaurant could seat and serve others, tip twice the amount. Hoffman says you should always leave a minimal tip, even with abysmal service. Tips are generally shared by the restaurant's workers.

• Takeout: Nothing is necessary. But if you receive some service, like a waiter packaging your food, then tip $1 to $2 or up to 10 percent. For sushi, tip 10 percent for its preparation, Hoffman says.
• Tip jars at fast-food counters: Nothing required; it's your call.