If I see the waiter is doing hard work so I will give him a tip after giving payment. If I am happy with the service of the waiter and he fully help towards our work given then undoughtfully I will give him tip.

Sometimes suppose my restaurant bill comes to 9$ then I will pay 9$ at recipient and 1$ I will give tip to the waiter.

It is not depend that the waiter is good or bad but we should depend upon his work then only we are giving him a tip.and the person who are asking or begging a tip don't give them because they fools people by asking tip and people give them.