Hey there,
well you can either learn certain anime faces at specific angles and draw them till they are stuck in your head
Option 2 would be to study the figure, head and face structure till you have a good understanding of it and are able to find ways to represent it as you please
then there's option 3, doing both. you learn from life and learn from how others have simplified it in ways that appeal to you.
Option one is the fastest if you just wanna be able to draw a decent character from a few pre-determined angles.
option two and three, at least on average take years of practice
I can guess from your studies that you aren't taking away much from doing them yet.
they don't look like very conscious studies, and thats not an attempt at a put down
I would recommend at this point, doing more studies that focus on getting the structure and face parts organized well and proportioned fairly accurately.
you can do allot of quick head studies that just get the general perspective and feature placement well
This kind of quick study will be more bang for your buck, especially if you're strapped for time.
and for poses you can get more learning of the basic composing in 3d space by composing many rather than taking longer to render out from a photo study.
and when you do study from photos,
the more you are aware of what information you are trying to absorb, the faster you can take it in
be mindful of what youre actually observing
hope that helps somewhat.
drawings real hard
theres manga artists in their 70s and 80s that struggle everyday to draw a nice anime girl