Well, you can deal with the build and develop relations with the top customer by knowing the concerns of the customer and being able to meet them. Secondly, you also need to know how to approach your customer, being polite to your customer and also being able to interact with them. Every customer has a particular personality, so you have to know how to approach each customer with your personality part-time. The second thing you have to have at the back of your mind is that the customer is always right no matter what, so even a tough customer can be substantial with the right approach and with the right tone. Also being able to meet their demands appropriately in due time, with apologies being offered intermittently alongside.