No one here is insulted by a tip. You only tip a taxi driver if he goes above and beyond — helps you with your luggage, etc. A ‘servicio’ line item of 10% is typically added to your restaurant bill and it is up to you if you want to leave more. if the service is extraordinary (not common here, by the way) you might want to add a bit more. I tip $1 per bag to bell staff in hotels — or up to $3 to $5 if we have a lot of stuff between the two of us. And it is common to leave $1 or $2 on the pillow in the morning for the cleaning staff.