This ain't much and it's taken me hours, but I decided to go back to my Belle model (ie, from the movie Belle) and this time build the eye and face loops from scratch and try to get that part of the face approximately correct for if I was modeling an actual person. I know from a "making of" article that they tried to keep their model fairly realistic with only concessions to make it sufficiently anime, so I figure that's a good approach here too.
It's definitely not there yet – looking at the left I can see I probably want to actually bring the brow ridge out more and the bottom corner of the mask out more to get more of a 90º v-shape pointing at the eyeball from this angle – but it's a damn sight better than my last attempt which just looked entirely wrong in this region and I couldn't work out why.
Faces are surprisingly difficult.
Yeah as soon as I voiced my dissatisfaction I had to fix it. I tried to add that 90º-angle-at-45º kind of look to the angle of the brow/cheek from this perspective, and also added more of a marked 90º angle from brow ridge to nose at the top of the nose and I think it's better.
Still not ideal – I don't think there's any working around the big anime eyes of my reference until I bung a toon shader on it. Still. Next up I'm gonna try to get them nose loops right and work my way down to the mouth and cheeks.
so the first image here is where I was at before I got started. I tossed it out and hard-modelled again from scratch. I think my topology is a lot better, and I had an easier time getting things set up this time because I made the separate parts I wanted and then assembled. This had the benefit of allowing me to spot where an extra edge loop might make things line up nicely and help me to avoid a bunch of 3-poles and 5-poles where I didn't want them.
Other than the fact I could make the nose a bit cuter and more buttony, I think I've made a vast improvement. I think here's where I should switch to modelling the body, possibly very roughly indeed, and rigging. I'm thinking of pushing from here into VRChat relatively quickly even if the head is a scary floating mask with no eyeballs so that I can at least puppet it and have done the whole thing end-to-end even if the model is unfinished.