Do area renders, it goes faster and you can concentrate on critical area's.
Lights?
One at a time, and tweak but keep their intensity LOW as not to saturate the main light or its shadows.

Think light, be light
Think shadows and be shadows.

it is a sensitive "game".

Poser 1, 2, 3, 4, 5, 7, P8 and PPro2010, P9 and PP2012, P10 and PP2014 Game Dev
"Do not drive faster then your angel can fly"!