In the blog, readers learn how to enhance the JWT response payload by adding custom attributes such as the user's email using Descope, a no-code platform for creating authentication flows. By leveraging Descope Flows, users can quickly create authentication journeys with a simple drag-and-drop interface. The process involves setting up a Descope account, creating a project, and using the "Custom Claims" action to add custom attributes to the JWT by specifying key-value pairs, like setting the key to "eml" for email and the value to "user.email." Once configured, these custom claims can be integrated into the flow with easy-to-make connections, and the resulting JWT can be inspected using the Descope Getting Started Wizard. The blog also encourages experimentation with various custom fields beyond email, highlighting the flexibility and ease of using Descope Flows for authentication needs.