I'm working on this as well. So far I have added the backboard decal which is glossy and reflects a little bit of the ambient light. I also wired in a spotlight right above the upper flipper as other people have shown. I used a white Ablaze 3 led wedge and it lights up the bookcase nicely. A regular 555 also works but the blue led that I tried messed with my eyes.
It's still dark in the back left corner and I haven't tried anything yet. Maybe attaching a spotlight to the ramp or behind the chair as terryb suggested.