By creating customers who highly value, even love what you do for them, to the point that they want more of what you can do and they are highly likely to be strongly recommending your brand/business to other people like them. This is true in any context – business-to-business and business-to-consumer.
The first step in understanding who your most valuable customers are is to define what makes them valuable to your business.
This might seem a strange thing to raise, because isn’t it obvious what makes them valuable to your business?