One important bit of advise i can give anyone doing their case study is to do something different and get off the damn hills hoist. To get a great mark you either have to do a bloody good job of it and i mean fantastic because over the years thousands and thousands of people have done it and im sure the markers have read everything. Or alternitively get ur ass into gear, actually do some research and try and find something that is out of the ordinary, interesting and that hasn't been regurgitated by every second DT student in the state. Impress ur teachers with something different aswell, it gives them an indication that ur interested in what ur doing and have the initiative to go beyond the 'easy way out' and do well.