What is sales?

Building relationships is a big part but it really boils down to storytelling. How compelling is your story? It needs to be compelling enough to move somebody to act. 

Sales is about moving people, and people respond to stories.

To practice sales, practice telling your story. Where did you come from? What problem are you trying to solve? What do you care about? Why? The more you can understand and verbalize your answers to those questions, the better you will be at selling.