Lydia provides a detailed tutorial on preparing and taping butt joints in drywall installation. She emphasizes the importance of creating a slight V-notch to remove rough paper edges, allowing for a smoother finish. By prefilling the joint with mud and using paper tape, she demonstrates how to ensure a flat and even application. Additionally, she highlights the need to address any humps or unevenness in the joint with subsequent coats. Overall, Lydia's approach provides a comprehensive guide for achieving professional results in butt joint taping.