Speaking of hairdo. A month ago, I just made some changes to one of my piece on my #portfolio website: http://xiataptara.com/
Below is an image of before and after.
Original image is at http://idrawgirls.com/gallery/portfolio/zombie-hunter-illo/
Here is the final original image.
Some tutorials you might be interested in
-How to draw Daenerys Targaryen
-How to draw Margaery Tyrell
-How to draw Katniss Everdeen