There are a few golden rules that you can follow in order to strengthen your relationships with customers and business partners:

1. Make phone calls instead of using email - it is more personal to speak to someone over the phone and it shows that you value the relationship.

2. Make every decision as if you did not need the money - this ensures that you will make the right decision for the customer/client and not because you need the money.
   

3. Put customer needs before your own - this ensures that you will always have the customers best interests in mind.
   

4. Give before you take - to create loyalty and a reciprocal relationship, it is usually better to give something before you get something. This shows that you want to make the customer's life better.