GIMP tutorial - Pencil Sketching I

I've been playing around with GIMP these 2 days, and have managed to create a simple pencil sketch which I'm quite satisfied with. This tutorial serves as a reminder of the lessons I've learnt while using the software.

1. Open an existing image. On the menubar, File>>Open. I've chosen an image of the beautiful Kyoko Fukada
   
   


2. On the menubar, Layer>>Duplicate layer. Select a copy of the image.
   


3. On the menubar, Layer>>Colors>>Desaturate
   


4. Adjust the dynamic range of the image. On the menubar, Layer>>Colors>>Threshold
   


5. On the menubar, Filters>>Edge detect>>Difference of Gaussians. Play around with the values until you see something you like in the preview window.
   

And that's the final image!

Some books on GIMP.