Im always impressed by how consistently you upload here, your linework is definitely improving keep it up!
I have never really posted something like this before as I have been nervous as I am a beginner myself, so please let me know if you dont want something like this on your page and I will remove it.
I think if you spent a little but more time on your construction, before putting down linework, it would help your studies improve . I have had some decent success following the method Marc teaches in Term 2 - Anatomy 1.
It seems like you mainly just draw the construction for the circle with a centre line and stop there. Whereas I think if you take it further, adding construction for the jaw, eyes, nose and mouth, it would help greatly with accuracy, proportions and linework.
I understand that doing this is quite tedious as I just want to draw heads without any construction but I think if we do this lots over time we will internalise it which would make it easier down the line to draw with less and less construction.
I posted an example below of the type of construction I am talking about.

Let me know what you think, if you agree or disagree, I am looking forward to seeing more of your work and progress!