The integration of Extended Reality (XR) technologies in education has introduced new opportunities for immersive and interactive learning experiences. However, the effectiveness of these environments depend on well-defined design guidelines that optimize usability, engagement and learning outcomes. This paper presents a synthesis of design principles in three categories: before the experience, during the experience and after the experience. A systematic literature review was conducted to identify relevant studies. The findings highlight key considerations such as familiarization, sensory feedback, adaptive interactions, cognitive load management and post-experience reflection. Additionally, this review addresses challenges related to accessibility, cybersickness and user autonomy in immersive settings. The study provides practical recommendations for instructional designers and educators to develop XR applications that enhance engagement and support meaningful learning.