Cool heads. I think the main reason you're having problem with 3/4 views is that the overall base head is not defined.
Jumping into features too early without resolving the tilt and base proportion. Remember that this is the base head.
People vary from person to person but it's necessary to commit the base head and base figure proportions to memory
so that you have a ruler. This is not easy and will take time but it's well worth it.
When I do demos for students working on the manikin head and figure, I look at the model, answer a few simple
questions, and then I don't need to look at the model anymore because I'm drawing the manikin. Once you get comfortable doing this,
then it gets easier to start seeing how the model varies and you start sight drawing more. When you observe you observe,
when you draw you draw.
A simple exercise you can do: If you do a 2 min pose. Don't draw for a min or don't draw for 2 min. Draw when the model
gets out of the pose. This will train you to ask the right questions and look at the overall shapes and form.
Hope this helps. Keep going