But do note that tipping practices vary so much around the world, so a
little research could spare you the uncomfortable situation should you
get it wrong. But generally, unless you're rolling in dollar bills, paying more than necessary is not always a good thing.
Some hotels leave a tip line on their bills open for you to add a tip. But usually they've already included an 18% gratuity plus additional room service or tray charge to your bill. If you don't look at your bill closely, you may end up tipping on top of the tip, which could be upwards of 40% or more. That's pretty deceptive when you think about it, since the hotel could have just note the tip they added in the tip line.
Another issue is with restaurants that automatically add or recommend how much you should tip. Usually this means calculating the tip based on the total with the tax, rather than based on the pre-tax food and drink balance. While it might seem like a small difference for one person, imagine how much they're profiting by the end of the day.
In short, consumer advocate and personal finance expert Christopher Elliott says that the best advise is to always calculate the tip yourself, and be alert if it's already been done "for your convenience".