Compared to some of the pro shooters advice here, I'm just singing in the rain, but here goes anyway...
I've tried all kinds of variations over the years...softbox, reflectors, different kinds of gels and umbrellas. Since I am more concerned about video, I finally ended up shooting mostly with steady on quartz video lights bouncing the light off of two white non-opaque umbrellas (one for the fill and one high up for the hair), and then my key light shining straight through a white diffuser.
My life is much simpler now, since I hire better photographers than I am to shoot the stills with their equipment, while I focus on the video.
Lots of good input though - I'm bookmarking this thread...
ADG