Work upside down. Create something in such a way that you have to rotate it 180 degrees to display/see it when it is finished.
I was really stumped by this assignment, and turned to Facebook out of frustration/desperation. Unbelievably, a friend was online at just the right time and immediately reminded me of ambigrams – a typographical design or art form that may be read as one or more words not only in its form as presented, but also from another viewpoint, direction or orientation. It really got me thinking, and so i present: my very first ambigram! Yes, it's the same if you stand on your head to look at your screen :)