Nice! I really like the vibe of your work.
Since you were asking about the planes of the face and shared a youtube vid, I'm sure you've already searched for the topic on there, so I won't link you to any of the videos by really popular youtubers... buuut, I did make a video myself about the topic when I was studying it a little while back that I think has some helpful tips:
https://www.youtube.com/watch?v=HdiQOwAjzCc&list=PLQuDZfUiMWTEhk-oaFb2s23dhUwU_Df0P
and also this one:
https://www.youtube.com/watch?v=ZYZhyVE8SSU
I'm a little embarrassed at the drawing now, but I think the info/tips are still pretty decent.
Also, a random video that came to mind specifically about the planes of the nose which I really liked is this one by Aaron Blaise:
https://www.youtube.com/watch?v=2bDlUN_8h0M
If I think of anything else I'll post it up here...
But a general piece of advice that has been helpful to me that I will share, is that there is no one perfect way to break down every face into planes because faces can be so different. There are some main planes to look out for , of course, but for me it was really helpful to experiment with all sorts of different ways to construct/draw heads as it has given more tools in my toolbox, so to speak.
Before I tended to want to find one perfect way to break down the head, but I ended up frustrated and with my heads/faces looking very similar.
Anyways, hope that's somewhat helpful!
Cheers,
~Shams