As the prevalence of augmented reality (AR) technology continues to increase, so too have methods for improving the appearance and behavior of computer-generated objects. This is especially significant as AR applications now expand to territories outside of the entertainment sphere and can be utilized for numerous purposes encompassing but not limited to education, specialized occupational training, retail & online shopping, design, marketing, and manufacturing. Due to the nature of AR technology, where computer-generated objects are being placed into a real-world environment, a decision has to be made regarding the visual connection between the tangible and the intangible. Should the objects blend seamlessly into their environment or purposefully stand out? It is not purely a stylistic choice. A developer must consider how their application will be used — in many instances an optimal user experience is facilitated by mimicking the real world as closely as possible; even simpler applications, such as those built primarily for mobile devices, can benefit from realistic AR. The struggle here lies in creating an immersive user experience that is not reliant on computationally-expensive graphics or heavy-duty models. The research contained in this thesis provides several ways for achieving photorealistic rendering in AR applications using a range of techniques, all of which are supported on mobile devices. These methods can be employed within the Unity Game Engine and incorporate shaders, render pipelines, node-based editors, post-processing, and light estimation.