In Italy service is normally included in the restaurant or bar bill, and additionally in most restaurants the so-called  "coperto" (cover charge), which ranges from 1 to 3 euros, depending on the restaurant, is automatically added to the check.. Restaurant staff members make low low salaries, so tipping is a good thing to do .  If you were given an outstanding service, a good tip -- 10 euro -- will make the staff happy, but you are not "compelled" to do so.

Tipping cab drivers is unusual, but appreciated -- especially if they help you with your luggage and provide you with useful info about getting around in that particular place.

Tipping hotel porters is appreciated. Same for the hotel concierge if he/she is helpful in making your stay easier or more pleasant.