At Restaurants: The words service compris on your bill mean no tip is required, but most locals leave up to 10 percent in coins. Tipping at bars is not expected.

At Hotels: One euro per bag; 1–2 euros for a housekeeper; 10–15 euros per restaurant reservation made by a concierge—half on arrival at the hotel, half at the end.

Guides and Drivers: About 25 euros per person per day for guides, and up to 50 euros for one who's nationally certified; a separate driver should get about half of that. Give 10–20 euros for private airport transfers, depending on the driver's wait time and the in-car amenities, and a euro or two for taxi drivers, depending on how helpful they are.

Source : CNTraveler.com