Umm, I will tip toe in with my opinion, lol.
While traveling, people should respect the culture as much as they can. Some write bad reviews on how some waitstaff in Italy (and other countries) are rude and ignore patrons. That is not really true.
Also, if a person wants to slip a euro or two to the waiter for something they went above and beyond for, then hey...whatever. But, a standard tip on the bill for a non-tipping culture is not needed.
USA'ers are brainwashed (or made to feel guilty) into thinking a tip is deserved everywhere. Everyone has their hand or jar out.
In the States, it's customary to leave a tip with table service. 15%-20% < for excellent service) is good. Though, it is aggravating that restaurants expect patrons to supplement the very low wage. Some retailers don't pay a decent wage. So, should we now tip the bag person for putting groceries correctly in a bag? Should we tip the cashier for ringing up our sale correctly? When does it end?
And, the tipping "entitlement" is way, way out of hand. There is no need to tip if you pick up your own take out. There is no need to tip at DD, McD's, or similar places.
I bring my own luggage in to the terminal to be checked. Tipping a person to put a tag on your luggage and make sure it gets on the belt from outside? - huh? In that case, would you tip the desk agent at check in? Would you tip the baggage handler? - The people you need to entrust with your luggage.
Tipping at a bar for every single drink is absurd. First, establishments rob the person wanting to enjoy a cocktail or even a simple beer.
One time, meeting my parents at a restaurant, we had a waitress who kept coming over to our table "every 5 minutes" which was overkill. She was a pita. I was engaged in some conversation with my Dad. She came over, rudely interrupted, never said "excuse me," and proceeded to say some gibberish about the food to my Dad. I glared at her with 'the look.' She hung back after that, lol.