/ic/ - Artwork/Critique

hey dads is there a particular way of studying heads that works best? I was checking loomis but I think it's confusing
I was going to try another book to see if I can have better results. How would you go about practicing with these refs? i follow his tutorials often and I've been trying the one about heads but I feel it's still a bit confusing

If you feel like it, please try drawing them, that could help me a bit