Man your progress through this sketchbook is pretty amazing, very inspiring stuff You also make me want to be a bit cleaner with my lines hehe... gonna have to try using a harder pencil and slow down next time I do studies (as you mentioned on an earlier page), seems like it's been quite helpful. Not a whole lot for me to critique honestly, your sketches really blow me out of the water. On the most recent digital study you've got (the portrait of the lady) her face seems to be flattening out on the right side a bit (her left), but otherwise everything is looking really good.

Keep up the great work, I'll be keeping an eye out!