I have been taking part in a sketching group recently and reacquainted myself with the method of sketching from the book *Drawing on the Right Side of the Brain* by Betty Edwards. While Betty has written a whole book, essentially and quite simply this method involves drawing UPSIDE DOWN! No, silly! not YOU!! (Visual of everybody standing on their heads and attempting to draw here! LOL LOL). Simply by turning the subject matter upside down and sketching it from that perspective produces amazing results!
It is based on the theory (for those of you with inquiring minds) that the left side of the brain is the *smarty pants* who *knows* what a chair, a nose or an apple looks like and bosses you around when you place marks on the page that don't match it's stored version (which does not allow for such things as foreshortening or the odd shapes that perspective or shadows produce). It's also this very precise side of the brain that keeps time and is good at lists!
However when the left brain cannot easily recognize or label a subject, the right (or creative) side of the brain kicks in and just sees the shapes and angles without trying to turn them into *something*. So, by working upside down and simply seeing those shapes and angles and repeating them, we produce a strange *map* which sometimes makes little sense until we turn it right way up. VOILA!!! Suddenly those ugly shapes become perfect shadows on a face or landscape. It's (almost) magic!
Of course it does have it's limitations as we can't turn a fresh vase of flowers upside down to sketch it, BUT we can take a photo and work from that, and over time, one develops the ability to be able to switch that pesky left brain off and work in right brain mode without the need for upside down subjects.