If he has plain, painted walls he could use Oriental stencil designs and make a big difference to the room that way. Examples of designs: Oriental ideographs (lettering), bamboo (growing, with leaves, not just canes!), even something along the lines of the images on willow pattern plates, simplified of course. All depends on how artistic he's feeling, and how daring. If he's interested, he can always try a few things out of some pieces of MDF or something similar (or a wall that's about to be decorated anyway).