You should tip the waiter $10, minus $2 if he tells you his name, another $2
if he claims it will be His Pleasure to serve you and another $2 for each
"special" he describes involving confusing terms such as "shallots," and $4
if the menu contains the word "fixin's." In many restaurants, this means the
waiter will actually owe you money. If you are traveling with a child aged
six months to three years, you should leave an additional amount equal to
twice the bill to compensate for the fact that they will have to take the
banquette out and burn it because the cracks are wedged solid with gobbets
made of partially chewed former restaurant rolls saturated with baby spit.

In New York, tip the taxicab driver $40 if he does not mention his hemorrhoids.
-- Dave Barry, "The Stuff of Etiquette"