Illumination systems cover a wide range of applications including fiber illuminators, projectors, and lithography systems. The design of an illumination system often requires balancing the tradeoff between providing uniformity, maximizing the collection efficiency from the source, and minimizing the size of the optical package. These tradeoffs will be examined for systems using lightpipes, lens arrays, faceted optics, and integrating spheres through a combination of computer simulations, hardware demonstrations and discussions.