At Restaurants: Round up, plus a little more for excellent service—say, to the fives (25 euros for a 22-euro meal).

At Hotels: Porters, a euro per bag; housekeepers, a euro a day at most; concierges only for something very special.

Guides and Drivers: No tip expected for taxis—round up and they'll be delighted; private drivers, 20 euros per day, 50 if they've gone out of their way. Group tours, 2–5 euros per person; personal tours, 20 or more.

Who Else?: If you charter a boat, the captain will let you know if the crew gets underpaid, and will collect a euro or two from everyone; tip the captain 50 euros per person at most.

P.S. Alec Mally, an American former diplomat now living in Greece, notes that since the introduction of the euro, tipping expectations have become considerably inflated, because people tend to round up to the next euro. Four euros for a 3-euro drink isn't unheard of.

Source : CNTraveler.com