Most of the service charges and taxes at restaurants and hotels are included in the tour price. However, it is often expected in many countries in Europe to leave an extra tip. This is in case of good or excellent service in restaurants, cafes or during guided tours. The custom of tipping varies in the different countries.
Tipping is not common in France, as a 15% service fee is already included in the final bill. However, tipping around 10% is not unusual for excellent service at a restaurant. Furthermore, tips at hotels and museums and are mostly between €1 and €2. The tip for tour guides in France is usually between €2 and €5 - per day.
Tipping in the United Kingdom (England, Scotland, Wales & Northern Ireland) is not necessary. For good or excellent services in restaurants usually, 10% of the bill is given as a tip, but at cafes, pubs or bars tipping is not expected. You should tip a guide or driver that you are satisfied with, about £2 -£4 per person per day. It is common to round up the amount of the charge in a taxi as tip, but this is not mandatory.
It is quite common to leave a tip in Ireland, around 10-15% in restaurants, bistros, cafes, spa’s and for private tour guides. For taxis, it is not mandatory, but quite common with about 10% of the fare, or round up to the nearest even number.
Tipping for the services in restaurants and cafes is quite common in the Netherlands for good or amazing service, about 5-10% of the bill. Many also round up the bill or leave the change. Do not tip for bad service. You are welcome to tip a guide that you were satisfied with. There are no fixed rules or expectations for how much to give. Because of this, every tip is highly appreciated by the tour guide or driver. When participating in a free walking tour it is often expected to leave a generous tip, as the tips are their income. It is not common to tip a taxi driver.
Tipping is not common in Italy, they will even (at first) refuse to accept your tip. If you would like to give a tip, insist on it. In case of excellent service in restaurants, you could tip around 10-15% of the bill. Furthermore, you could tip €5- €10 for a guide.
For more information on tipping worldwide, please see http://www.whototip.net/