Hope you can understand my weird wording and hope it helps a few.

Have you thought about making a guide focused on expressions for realistic animals? You have a section for it in this one, but it's so short and I feel like it could be expanded upon further. Specially because there are literally no guides whatsoever out there for realistic animal eyebrow expressions. All guides are either about humans, or cartoonish faces.
I have a realistic art style and struggle horribly with drawing facial expressions. I can't quite grasp on how to make my creatures emote without slapping human eyebrows on them like you see in more cartoonish styles. Plus it often confuses me how to combine the brow positions with facial muscle cues to get the right emotion. Even looking at the tips in this guide, I don't know how to apply them to my artwork since our styles are so drastically different -.-''.

"95% anxious - phone call"
...where's the lie though?
I hate phone calls ><
This is a good one :D
Though, I know about jaw hinging and such, but getting an open mouth to look "right" is still difficult without drawing an underlying skeleton. Hm...
Pupils are another big one, but it's interesting to note how most of the time, artwork actually 180-opposes reality with the pupil itself. Fear or excitement make the iris muscles contract, widening the pupil, but in most art these same instances of high emotion are better conveyed by shrinking the pupil. I guess it's exaggerating that "wide eye" look?

No such thing! I can't count the number of times I've seen a "tutorial" that started with lineart then bolted straight to a masterpiece with NO explanation how to get from point A to point Z; that is beyond just SHOWING the art, like the artist was so oblivious of their own advanced skill, they were just like, 'Okay, make a box for the torso and another for the pelvis, now reproduce my masterpiece by staring at it until your eyes fall out.'

To be fair, I've never done a tutorial myself. I've done figure studies, and some people consider those helpful, but that was just me breaking down a figure into basic forms for practice.
Your tutorial was elegantly straight-forward, concepts worded and depicted visually in equal measure. Your segment on animal eyes, canine ones, I found especially helpful; and I hope to apply it from now on to my OC.
I never wanted to give her eyebrows, because her nature is lycanthropic, but I didn't think I could emote well enough without them.