draw only 

added some shading on the face & details on the necklace 

added black shading on the hair first with lasso tool & added some details too

ended with highlight on the hair lines & highlight on the overall portrait

finalise with some highlight shadow around the portrait itself

draw only

added some shading & details mainly on the face

added black shading on the hair with lasso tool 

added more black shading on the hair part with hard round pressure and opacity brush

ended with highlight on the hair lines & highlight on the overall portrait (face)