These are some nice faces like you said some of them are too wide while others are too narrow. I also think the nose area would pop out further than you have in some of these as well blocking more of the eye area. overall nice heads though.
also for extreme angles if you see yourself drawing those a lot then continue practicing those but if not I would stick to the more tame face angles so that you are really good at those and use ref for the more extreme angles
I've been learning more about drawing faces, i decided to go on to the parts and practice all together later because i really want to start rendering.
Then i tried the parts...
After this atrocity i decided to learn more about shading, so i studied that some more and i think i got slightly better.

The grind goes on!

Thank you for the nice comments!
Today was a slow day and i didn't produce much, but i wanted to share something that made me really happy, i feel that i have overcome a obstacle that has been a struggle for such a long time.
I was feeling demotivated while trying to structure the heads and decided to see how it would change the way i usually draw.
It may look silly, but today was the first time that i ever felt real joy while painting. For such a long time i hated doing it, and because of that, i focused too much on doing just line art, because of that my pieces would never be trully finished, and i would not give everything i have.
The painting is far from being good and the page is a mess because i wasn't planning on posting it or anything, but i want to keep this as a register to myself.
I hope that this is a starting point, and from now on i can trully give my 100%.

Thank you Lukie!
I started to dip my toes on rendering the face.
I'm trying to limit the number of values i'm using so i don't feel overhelmed, using only hard edges brushes, because i heard i will learn more this way...
I've introduced mid tones in this one:
I'm gonna have more caution to keep things less messy next time.
Let's keep practicing!

I've made some more drawings from reference... painting is difficult, but i will get there!
I've tried to construct some from imagination too.
For last, i decided to try to draw my D&D character, i applied some suggestions that i've received in discord, and gonna try to paint it next! I'm really happy with the result .
Wish me luck!
Insane. These are some seriously good drawings! I should probably start copying you and do some personal work too. The studies are looking good. Your linework on that second face is really good, I think just pay more attention to the reference when shading cause a few of those shadows don't exist in the photo. Keep it up!! (I'll definitely start forcing myself to use a hard brush from now on)
@Lukiesartventure Thank you for the feedback! I got carried away and made some crazy shadows hahaha. I'm going to be more careful next time.
I started working on my friends characters too. The first one is Wim, the Tortle (turtle person) druid!