If you think that when you finish drawing the face, which is perfect, the most difficult part is over and nothing can ruin your portrait, then you are mistaken. The truth is the hair is pretty tricky part of the drawing, it can be difficult to draw realistically. Sometimes you can spend more time drawing the hair than it takes to draw the facial features. When you are doing the hair the fist layers of the charcoal usually look really good, nicely faded and smudged, still light toned and not contrast, which is not enough for the perfect realistic hair. That is why when you decide to add some more darker shades of the charcoal you will find out that the charcoal pencil (or any kind of charcoal you are using) will be sliding on the surface, not drawing at all or it will be scratching the lower layers, so the top layers will look damaged. The final results are not going to be great. But don't worry, I've created a simple drawing routine for the hair and I am happy to share it with you. Here is My Tip #8.
The drawing method is very simple: charcoal stroke - blending stump - erase and repeat. Always keep this process in this direction and you will never have problems with drawing the hair. The first two steps are the most important, the last one is optional. Let me explain to you how exactly this routine helps. Charcoal is hard to be blended and faded without a blending stump or a tortiillion, that's why it won't create realistically drawn hair by itself. No matter what type of the hair you are working on you need to create smooth natural lines and shades to make the illusion of realistic hair. Try to achieve that with maximum two layers because the more layers you get, the more it looks fake. You can see on the video how I'm actually using this method, except the erasing part. And I hope you try this method by yourself and it helps you to reduce the time of drawing the hair and make it perfectly realistic.