The most common use of up lighting is in a recessed cove around the top perimeter of a room. To maximize light output use a T5 fluorescent or LED light source that will wash the ceiling with light. This helps to create a brighter ceiling that bounces and reflects light throughout the space without glare. Combine this with lots of natural daylight to increase the overall light levels in a room.
It’s important to understand that even on a sunny summer day natural light from a single window is not always sufficient to thoroughly light a room and of course this is especially true come nighttime. Additional light sources near your window will allow you to subtly fill out the light scheme and achieve a balance so the space feels beautiful at any time.
Wall washers either installed on the wall or aimed down from the ceiling are used mostly to highlight decorative features such as an art piece or a textured finish like a brick wall. However the psychological effect created by lighting the walls can make the whole room feel much brighter.