I think I am being a good Manager when my employees feel they can come to me with any calibre of problem. From on-the-spot cash register problems, to a customer service problem spawning from an earlier issue. I try to be honest and keep my integrity with a customer I know is right, or wrong, yet still have them come back AND talk to me again.
Most people realize that even the most dictatorial of positions are filled by flawed human beings just like then, who have dealt with the dream and nightmare customers a dozen times that day. The biggest thing you have to deal with is creating a real connection between people who just want to be satisfied (or more), and a head office that wants to do the job with as little resources as possible. Everything else really comes with effort and honest intentions.
Your job as a Manager in the human resources department is to analyze the positives AND negatives in all of your employees and give them a chances to specialize in that. Naturally if a someone hates to do something, they won't excel in it and vice versa. But they also won't know unless they're given feedback by a person who sees them operate everyday, and paid both compliments and criticisms.
I believe customer service is purely from the heart. People who see themselves and can empathize with everyday situations. One thing a true professional realizes is that there are 2 basic reasons one comes shopping for necessities. One is that they must provide for the famished mouths at home ; Number two is that they need a change and possibly someone to talk to. Everyone (including myself) who is good with C/S realizes that every customer has something to offer them as long as they have something positive to offer the customer.
Excellent customer service comes down to a few key elements. People need a changes, and come to your place to make it a positive change. They want to feel appreciated for trading their money to you, which is established by paying punctual attention and not making them wait too long after starting to serve them. They need a quick, positive connection to know they are dealing with someone who is flawed just like them. And the number one is that they need to walk away with what they came in for or something similar.
Hope that helps.