Definetly share the sentiment about perspective. It's really rough, and I tend to forget to do it properly. I also don't think many of us accuratly measure head proportions unless something looks really off. It's important to practice at first and to have the knowledge, but as you do more gestures, exercises and so on, you sort of start skipping steps and go with your gut.
Kind of like driving manual. At first you tend to pay close attention to the clutch, signals, and lots of technical stuff, but at some point you simply start going on auto pilot unless something demands your attention.
The alien looks cool btw, also love the hair and the clean proportions on the 3/4 angle.
