Although I've done some much more recent models with 'red' hair (makes Vikings look pretty fierce!), the only pictured one I could find is my Shieldmaiden.. painted (and photographed badly) 3.5 years ago!
Redheads are probably among the trickiest to get right, mostly because you'll have to mix colour for the right basic tone.
What I like to do is the following (names of the old Citadel paints, you'll probably be familiar with those):
Standard mix: light reddish-brown (Bestial Brown) with some darkish orange (Blazing Orange). [strength of orange tone dependent on preference]
For the first coat, mix some dark brown (Scorched Brown) in with that mix - this colour should often barely be visible, but Tauriel has a lot of texture in her hair!
Colour in most of the hair with the standard mix.
Add some 'blonde' (Desert Yellow) for highlights.
Add a tiny bit of beige (Bleached Bone) for the final extreme highlights.
Similar colours (with superiour skill!) used on these guys -
not my work but Cubster's on the Warlord Games forums:
As you can see, more brown on the first, more orange for the second guy.