The dog poo expression is quite normal,and it takes time to perfect it.... even if you give them 10,000 QR for 5 minutes work, they would think that since you gave that much, you can surely give more.

I would usually give a 50, and then another 50 after they whine (after the dog-poo expression)... Then I would say this is much more expensive than it used to be, I'm not giving anything more.