Not to beat a dead horse, but unless your teacher specifically said only head shots as your self portrait, then you are free to take a full body shot of yourself. I recommend using creativity to show your personality, just using props (although helpful) can seem cliche if you can easily substitute your body for anothers. Make it personal so your teacher can see that you put a lot of thought into it... although since it's due tomorrow, I would just make sure it doesn't look like you waiting til the last minute.