I basically zoomed in on another pic a drew this week, so if you want to see the full version, it's here: topic87221.html
Alrighty, here goes.
The first pic here is just the outline. I usually colored digitally over sketches that I've drawn by hand.

The first step you gotta do is choose your base color. For this girl, light brown. So to make the original lines of the hair show through, set the layer to Multiply, and then color the area completely with a basic brush. I usually just blob the color on, and then erase the parts that went out of the lines.
*tip* Instead of using a solid eraser, I always use the Smudge tool. I think it helps to get the tips of the hair more wispy and less blocky. I dunno.

Next, I add shadows. Set a new layer to Multiply. Change your tool to the airbrush, and select a slightly darker shade of your base color. On this pic, I also made it a little more vibrant because I decided I wanted brighter hair
Take the airbrush and color in the areas that would be coverend by shadow. Usually, I make the tips of the hair dark, and also the roots, leaving an area of shine in the middle. Also be aware where strands of hair overlap each other.

The next step is just like the last one. New Layer, set to multiply, using the same tools and the same color. Just go over the same areas again, making it a little darker.

Next we add the highlights. New layer, this time set it to Soft Light. Still use the airbrush tool, but change your color to solid white. Now, find the area in the strands that would catch the sun. It's usually around the middle somewhere. On this pic, I pretty much made it so that each section of hair had shadow, base color, highlight, base color, and then shadow. But there are a zillion different ways to draw hair so don't just follow this.

Final step, and that is just reinforcing the highlights. Do the exact same thing. New layer, Soft light, airbrush, white, and go over the highlights that you already added, making them a bit brighter. Easy peasy! Now the hair should look all shiny ^-^

So that's it! Let me know how this was xP
