Exceed expectations, always be professional, dress appropriately, be on time to work, let upper management know you are interested in a promotion when the timing is good if they are unaware. Customer service in stores is lacking in many places in recent years. Remember that every time someone complains there were ten other people who were unhappy with the service and didn’t bother to tell you. They might never shop in your store again or tell ten friends their discontent with your store it worse post online. A complaint told to an employee gives the store an opportunity to improve; it’s valuable information. Let the customer know you’re glad they told you and see what you can do to resolve the issue.