The document discusses effective user onboarding through in-app product training, which allows for interactive learning within the application. It highlights various training methods such as onboarding emails, video tutorials, and one-on-one demos, emphasizing the benefits of in-app training, including increased user engagement and real-time support. The onboarding process can be customized and tracked for better visibility and efficiency, concluding that in-app training is the most effective method for user onboarding.