I like the soft light, I can't really focus on an O when I have a sun simulator shining in my face. Then when I close my eyes I see light rings of light like I've been staring at the sun too long.
So I usually turn off the bedside lamp and turn on the night stand across the room. It just adds sultry dramatic effect to my mood.
Candles are wonderful too. I spend some time with a hobbyist once, and he lit up the whole room with candles. I felt like the sexiest person alive. oh the thought of that just riled up my nether regions. Gotta go :P