Personas, scenarios, and storyboards
There is no such thing as a "typical" customer. If you want your customers to feel like they're more to you than just another face in the crowd, you need to think about what makes your customers different from all the other people in the world - in other words, their story. Usually you can't do this for each individual customer, but we can draw on our research to create descriptions of several different kinds of customer, each with enough detail that we can understand how that customer will experience their interactions with your company.
There are a few different approaches to doing this. Personas are descriptions of hypothetical customers. Scenarios are brief stories involving these hypothetical customers. Storyboards are the same idea but have a visual, comic-strip-like format rather than being written. But no matter which approach we use, the point is to help us (and you!) really understand the customer's experience, from their perspective, so we can design an experience they love.
Here's a persona we created in the process of developing web-based advising resources for college students. This purpose of this particular persona was to make sure we considered the unique needs of transfer students. We also developed personas focusing on the unique needs of veterans, first-generation college students, and so on.