I'm sorry @Fidney, but most of these are cropped too far from the chin.

Please remember that, while we want all cuts to include a little bit of collar, the ideal cut at the same time only contains 2-3 pixels beneath the chin. Since in some sources like this one, the person in the image may have a longer neck than usual, this would be quite difficult to achieve naturally.

Here's a video of the process on how to nudge the collar upwards: