>no one has touched on the topic of topology flow
God damnit, /3/.
That's a really fucking important concept, and is something that can actually be learned through tutorials.
No one ever talks about it here, and I think that's a shame because it's important to understand.
There is usually an objectively correct way to model topology when it comes to characters. At least, when we're talking about correct loop flow and pole placement for animation.
A lot of it has to do with anatomy, muscles, how skin deforms, etc, which depends on the subject of the sculpt/retopo.
Humans, for example, generally follow the same facial loop topology, with very little differentiation on the matter.
It almost always follows topology that mimics standard muscle structure and human anatomy.
You will always have loops around the mouth.
You will always have loops around the eyes.
You will always have loops from the eyes to the mouth, or around the nose.
You will always have poles around the corners of the eyes, and mostly always on or around the cheekbones or side of the head.
That's not to mention body anatomy, which has it's own list of bullshit you need to understand.
For things like the OP's pic, you'd really benefit a lot from learning human topology/anatomy, and applying the fundamentals you learn from doing those to anything non-human.
You've got to understand why things flow the way they do, why certain poles are where they are, and why things are segmented the way they are, and THEN try more complex stuff.
Look up tutorials on how people do topology, and put in the work by churning out heads until you get it correct.
There is a fuckload of experimentation that goes into this when it's for something that is not easily researched, such as a specialized model, like others here are suggesting.
That's not to say you couldn't just wing it and get it right somehow the first time, but it's highly unlikely due to the absurd amount of things you would have to have knowledge of.