Infact I do not tip anyone at all … coz anyways they include the service tip in the final bill … so why spoil them with the tips ! 
When i went to Pakistan , the hotel bell boy that took my stuff upstairs expected me to give him a tip and i took out 10 rupee note for him , he looked at me disapprovingly … that made me so angry , I immediately took that 10 rupee note from him and refused tipping !
Tipping is a bad culture … it only promotes bribery ! I think 