
Step Two

With your paint brush select a lighter color (I used #B6936D) and draw in a few lines. Dont' worry about it being pretty. You just need some lighter color in the general area of the hair highlights.
Step Three

Now with a darker color, do the same for where the shadows would be (I used #342008).
Step Four

Select the smudge tool. Use a standard round brush about size 5, and strength around 70%.
Step Five

Smudge around in the direction of the hair. Don't smudge too much! You want the different tones to remain. If it all smudges together into one color, then it won't work.
Step Six

Now choose the dodge tool, size 3, range midtones, exposure 12%. Just draw some lines (again, in the same direction of the hair) where the highlights would be. This is accenting strands and emphasizes the highlights later on. Do the same with the burn brush (midtones, exposure 48%).
Step Seven

Now go to Image > Adjustments > Brightness/Contrast. Increase the contrast so it looks similar to this example picture. This makes seeing the differences in color easier. Then choose the smudge tool. This time you want size 2, and you might want to increase the strength a little. Play around with it. Because the brush is smaller, you can make much more detailed and defined strands of hair. Smudge in the curved directions of the hair.
Step Eight

Now you can select the eraser and carefully erase all the extra color outside of the lines :) See - it's starting to look nice.
Step Nine

Because we increased the contrast before, the hair may look too bright to you. Decrease the saturation to your liking. (Press Ctrl+U to bring up the saturation/hue window)
Step Ten

Also in the Hue/Saturation window, you can change the hue of the hair. In this particular example, I've chosen a blue tone. Happy hair creating. Don't be afraid to play around with contrasts, colors and techniques!