FIRST: I like how you draw eyebraws!!
I think drawing hair well has a lot to do with shading and lighting. Honestly, drawing anything well just comes down to practice and experimentation so I don’t have that much advice. But I really like the hair in the last picture! Especially the friziness. It probably looks nearly, if not just as realistic as the hair I draw. I personally, find hair to be challenging in realism..
Sketching with no reference is like hiking without a map!