How do you deal with different types of customers in a professional manner ?

First : You To Define The Needs Of Each Customer

Second : Each Customer Should Be Treated According To His Needs And Problems If There Is One Individually 

Third : You Should Always Keep Up With The Customer For Any Updates Or Feedback

If A Customer Is Angery, You Should Be Calm Enough To Calm Him Down, To Understand His Problem And YOU SHOULD NOT TELL HIM EVERYTHING WILL BE FINE, Instead, Tell Him You Will Inspect The Problem And Seek The Solution ASAP

A Loyal Customer Shoud Not Be A Satisfied One, So Always Keep To Attract Their Loyalty By Different Means

No offence to any particular, its the way i look at!

Customer is always RIGHT, it is the first basic principle to start with, and rest all secondary.  What I have noticed being a customer the people sitting on the other side of the table (customer relationships) normally have the mindset that customer is always WRONG and knows nothing. So once the mindset is like that from where come in the professionalism.