tbear - 6:42 pm on Aug 15, 2012 (gmt 0)
I make sure that the loudest segments just barely touch the overload point.
You are probably best to keep out of overload altogether, to get the best audio from digital. Digital sound is not graceful, at all, when it enters distortion/overload levels, unlike analogue.
I usually go for between -1 and -3 dB.