>>1375628 you've gone over your lines in various places so look over it and fix them, also, i notice that you're using strokes.In Illustrator, since CS4, there are variable width profiles for strokes. These are essential for lines which have visible endings, they really do look better when the endings taper off into a point.
Also, for things like hair ends, I think it's better to use multiple lines instead of one continuous line, and if using strokes, use a variable width profile on the individual lines. It gives a nicer effect in my opinion. You should be able to see what I mean on the attached image. Also, always, ALWAYS check your work as you go and fix problems as soon as you see them, that way you shouldn't miss anything.