It's jarring to have all of these voluptuous curves and anatomical detailing all over her body (except for the knees, hidden beneath the bottom of the frame), with attention brought to her triceps, her core muscles, her face and her hair, and yet that neck is just... *merp* two parallel lines.
I'm clicking around some of these thumbs in the "You Might Also Enjoy's" and that seems to be a recurring trait in these designs.
I recommend devoting some time in the sketchbook to some lady-necks at different angles. I think it could help out!
I can't say shit- my feet are terrible, so I gotta follow my own advice on that front.