Eliminating Hard Edges in Portraits

I have put the darks in around the face so that I can feather off around the sides of the face.  There should be no hard edges here, so that the face appears round and disappears behind and into the hair.  To feather off from a very light colour (i.e. the flesh tones) and into the very dark gap between the face and hair, use a bright mid-tone.  I have used a clean mid-tone orange and gently brushed this into the dark.