I did some quick paint overs of the faces
You have some things that are close to looking solid like the eyes and nose. Keep refining them more. The next time you do a face, focus on the proportions of the face. Make sure things are lined up better. Right now the one thing that stands out the most is the ear. Right now it's too small and the anatomy of the ear needs work.
In my paint overs, I hope to show you a bit of how the face works in basic planar shapes as well as how the skull should look underneath. Understanding how the skull interacts with the muscles and skin above is very important so make sure you have a skull reference handy. Have multiple references of faces from all different angles. If you can, take photos of your own face to see how some things look. Another thing that stands out is the connection between the head and neck. I painted how the connection can be fixed. Besides these things, this is a good start. With some more reference and time, you can make this head better or use these tips for your next head model.
