Shape is very important when it comes to ceiling lampshades. Upturned designs will help to reflect and disperse light over the ceiling and around the room (making them perfect for living rooms). On the other hand, narrower downward-facing pendants are great for directing light towards a chosen focal point – for example over a dining table or kitchen island.
In terms of color, it goes without saying that lighter tones and more translucent or hole-filled materials like rice paper and rattan will help to diffuse and maximize light, while darker tones and opaque styles like metal lampshades will usually direct light downward rather than out. There are some exceptions of course – lampshades with copper, gold, or chrome interiors will reflect light, helping to fill your room with brightness despite a darker design exterior (like the black lampshade above).