What not to do
Thinking or hair as ribbons is a good help, but not enough. You must also keep in mind that the hair is attached to the head. The round shape of the head influences the way the hair falls and the way it should be shaded.
The parts of the hair that is closest to your light source should be highlighted. This is usually a halo like shape on the top of the head and where the hair bulges out.
The parts of the hair that is furthest away from the light source will be in shadow. The darkest places will be where the hair is in shadow cast by other objects, like the back of the head or another part of the hair. Remember that the 'ribbons' are layered, so one ribbon can cast shadow on the other.
There are a few things that are important to avoid when shading hair:
* Pillow shading or cylinder shading: This is where you shade each lock of hair mechanically starting with the darkest color by the outline and working your way into the center with lighter and lighter tones. This is the shading for a fluffy pillow, not for hair!
* Illogical and flat shading: This is when you shade the hair and forget that head is a round 3d shape or where your light source is. The highlights and shadows should tell how the head is round and what parts of the hair is closest to/furthest away from the light.
Imagine where the light is coming from - where would it hit? Where can't it get to? Drawing highlight where there should be shadow will make your shading look off - getting it right will create an amazing 3d effect.
This takes practice, but don't worry - as long as you THINK about this while you shade, you will improve.
* Helmet hair: is when you get the 3d shape right but forget the complex structure of the hair... even very straight hair will not lie in neat symmetrical rows or form one solid shape. Think about adding a little variety to your shadows and highlights - do jaggy or zigzagging lines of highlight/shadow in stead of straight ones and draw the layers of hair asymmetrical and lively. Don't draw highlights as one continuous zone, but let it stop here and there. And add a few stray strands or locks to spice things up.
Here's a reference pic that should spell it out:
I had a LOT of fun doing this pic *giggles*
See how just a semi-decent shading will do a lot of difference, even on an ugly outline like this.
Also notice that the layered effect is not achieved by drawing very obvious lines between layers. You can do a few of those, depending on your hairstyle, but basically the placing of shadows and highlight will show that the hair is not one solid mass.
>>> next page, Doing the outline >>>