Some Greek Mask examples...

I have other examples that students have made in class, but here's some to get you started.

You should have ONE MASK for EACH CHARACTER in your play.  The masks should reflect the KIND OF CHARACTER THEY ARE, and their EMOTIONAL STATE.

I like that this one uses interesting material (the hair!).

A little blurry, but I like the colors and the different ages of the characters.

This is just a good starting point for those of you who may have no idea how to structure a mask on paper.

If you've got animals in your script, these are good ways to convey animals. 
(Don't forget the emotional state!)

For a good challenge, make your mask three dimensional. 
THESE ARE SO COOL.

Check out the Fu Man Chu on the mask at the bottom right. 
And the expressions on all of their faces!