Safty-Pin
Here are the images to use:

 

<-- FRONT (*Click ME for full size for shirt use*)

 

<-- BACK (*Click ME for full size for shirt use*)

Instructions:
•  Get a completely white shirt (doesn't matter if it's a t-shirt or a tank top, etc)
•  Print the images above on regular paper
•  Pin them to the front and back of your shirt as indicated (safety pins work good)

 

 

Example from Last Year: