How do I expand beyond selling just one thing to a customer?

Selling the one thing and stopping there leaves value on the table for both of you, and it usually comes from seeing yourself as the seller of a product rather than a solver of the customer's problems. Widen how you see your role and the openings appear. Customers rarely have just one need; they have a cluster of related ones, and the moment they trust you with the first, the others become approachable. Expanding is not pushing more product. It is following the trail of problems the customer already has into the next place you can genuinely help. After you deliver on the first thing, ask what else in this area is frustrating them right now. Listen without pitching. The next sale is usually sitting in their answer, waiting for someone to notice it.