I use the airbrush tool sometimes- be sure to use a really small brush when you get close to the hair. It is very difficult to use the magic wand and l@sso with hair sometimes- because it looks like you cut the picture out and pasted it on another bg
I just pick a nearby color with the eyedropper and then airbrush away! When you get close to the hair zoom waaaaaay in- sometimes I work at 600% for fine details.
Also, changing it to black and white is a little more forgiving than color
Another note (forgive me if you already know this)- don't worry if you make a mistake with the l@sso and/or magic wand. Just wait til you're done- then select the inverse and l@sso back your mistakes then select inverse again, etc. etc.
HTH