This was a technique I learnt in Illustration, very easy and very effective. The project involves firstly taking a photo of your subject, then placing the photo onto a light box with your drawing paper over top. Then taking a black ink pen start sketching in your shadows and leaving the highlights. Easy!
You should try it! If you don't have a light box try placing it up on a window with the sun coming through. And don't forget to post it on your blog so we can come and take a peek!!