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Great work capturing the angle of tilt of the head. 
I was also at this stage of drawing heads for some angles I still am. I find that sticking too much to the loomis head method makes your head look a lil weird. Although it helps with the proportions, I think freestyling based on the reference and then trying to fix it using the loomis method works best. 
Also try using one darkest line instead of multiple ones. If you're not sure of what line to put down, use pressure sensitivity and draw light lines first. 

It looks like you're focusing on eyes for this one. Maybe try flipping the canvas. You'll see whats weird. The left eye (screen left) is a lil smaller than the right. otherwise the eyes look great. Just try not to use scratchy lines.

You're focusing too much on the tonal values and small details without keeping in mind the overall form and perspective of the portrait. The hair looks stiff because you're using stiff and uninteresting lines without any variants for the hair.