It depends on the function. If it is purely decorative, then the material options are wide open. Translucent materials like silk, parchment and even thin sheets of wood create a warm inviting glow. You just want to make sure that they are not the only source of illumination or a living room will look like a lamp shade showroom, or an elegant pinball machine as your eyes dart from fixture to fixture. If the purpose of the lamp is for reading, you can use an opaque shade or a semi-translucent shade to help direct the light more towards the work surface. This type of shade benefits from a translucent diffuser on top to keep from creating a defined pattern of light on the ceiling. Lamping-wise, the less heat and UV the light source emits, the longer the lamp shade will last.