I don't live in a tourist area but certain places expect a tip from foreigners because it's what they have got used to, especially the 2-3 bars that the foreigners frequent in the local area. I don't understand why people tip in these places, over-priced beer and food with lousy service, even the lazy waitresses look like an advert for Michelin tyres!
Now I will often say keep the change after eating out (if under B40) if I've had decent service, normally it's gratefully received. Poor service then definitely no tip.
I know a guy who is a generous 'tipper' who thinks he will get special attention next time by tipping. If it makes him feel fuzzy good inside then good for him, I'd rather save it up for a donation to the local school for the blind. A good family friend told me that excess tipping by anyone is considered a character weakness and is frowned upon (but obviously accepted!)
J.M.O.