I once read a book "Drawing on the right side of the brain" by Betty Edwards, in it there is a fantasitc exercise that is very enlightening. This is good practice to get your "seeing" skill's for when laying out your guide drawing on your canvas or surface. Pick a subject to draw, not to detailed, and do your first sketch. Your drawing doesn't have to be a finished work, just make sure you layout out the geometry to get the overall picture, like you would when preparing a piece for painting say. Now, using the same image, turn it upside down and do the sketch again (upside down as you see it), once done compare it to your first and I think you will be very surprised. What is happening is when we look at things we say 'there's an eye' and although we see the eye we want to draw our brain fights this and we end up drawing an eye that is more like our own interpretation of an eye. That is, if we were asked to draw an eye from memory then copy an eye from reference there will most likely be more similarities to our own version than the reference. Because we turn the image upside down we can more easily see the 'shapes' we need to draw rather than an 'eye'. Anyway, give it a go and see what you think, I know I struggled when I first started the upside down sketch but I was getting more comfortable bby the end. Post up your sketches if you like and let us know what you learned or if you noticed any 'brain shifts' Cheers, Mick.