Nice portraits! It's great that you're going all-out and finishing these.
Maybe this post/video will help:
Also, I know Marc has said to start with a soft brush but I disagree a little bit — not completely, just about the type of softness. PS's standard soft brush is like an air brush, which can be difficult to get nice results with. A lot of beginner drawings have an overly-airbrushed look where forms get lost and look blurry. (Even in pencil, like this. Compare to this where they started with hard edges and blended, & another.)
A fuzzy brush can exacerbate that. Another way to soften a brush is to use one with hard edges (even a square brush) and use extremely low Flow. Like 1-3%. Try it!
Some more nice examples of blocked form to softening:
EDIT: here we go! I think the section title is too harsh, but just happened to find a similar explanation from Proko (page-search for Self-Delusion): https://www.proko.com/top-7-digital-painting-mistakes/ — the two side-by-side portraits are a good example.