What if physicians earned tips? Wouldyour services warrant a 20% average?While you're not likely to put a tip jar on thecounter next to the tongue depressors anytimesoon, the working stiffs who do rely ontips are finding that their average gratuity isrising above the regular 15% over the pastfew years. According to the , it's now generally acknowledgedthat a 20% gratuity should be given forgreat service at a restaurant. A recent Zagatsurvey found that the average Americandiner leaves an aftertax tip of 18.8%, whichis up from 16.5% in 2001. It's still fine togive only a 10% tip for shoddy service, butmake sure it's definitely the server's fault, asslow service could be the result of an errorin the kitchen. Also keep in mind thatservers often split their tips with busboysand hosts. Outside of a dining establishment,20% is a good rule of thumb for biggerbills. For example, a dollar per drink is afine gratuity for a bartender, but if you'reordering multiple expensive cocktails, 20%is more appropriate.