Things to note: 1. Try not to draw each and every strand of hair. Even when it's an extreme close-up the only strands that show up are the ones closest to the viewer. Doing this can prevent the image from becoming flat. 2. The lighter the hair tone, the more shades will be visible. Shown above are the colors used for each hair color. The blonde has more visible shades. The stronger/closer the light source the shinier hair will appear.
A lot of people have asked me how to avoid the muddy blending or soft looking drawings. The simplest way for me is by using the basic Photoshop brush, hard round brush. The brush is pictured in the sample page. I tend to use the soft round brush very sparingly. The tutorial piece was done using only one brush. The opacity ranges from 50% to 90%. I've included this brush in many of the downloadable BRUSHES HERE Limiting your color palette, and tools until you get comfortable, will make the learning process easier/quicker. Traditional and digital tools. Play around with the brush, also noting that understanding basic color theory helps in avoiding muddied colors. Hope this quick tip helps!