Keep a positive attitude. Provide the right service the first time. Help them solve their problem. Plan your day to achieve your goals. Keep to your plan.
Tips are bonus for an employee who cares about doing the job well.
So take a minute now, and before you tip, to consider what good service is and when tips are appropriate. Good service should be attentive without being intrusive. A good server speaks clearly and pleasantly, deals with questions in a positive and enthusiastic manner, yet shouldn't be overly familiar with the customer unless the customer encourages such an interaction. A good server also acknowledges and sincerely apologizes for a mishap or a mistake in service, and offers to compensate for the error. Service dictates tipping.