When purchasing graphic tees, you'll need to think about three things 1) the response that the graphic will get from other people 2) How colorful the graphic is and 3) How this graphic is different from all other graphics.
Consider whether or not the graphic tees are appropriate for the event that you will be going to based on the the style and cut of the shirt. For example if you are going to play tennis then you might want to wear graphic tees with the picture of tennis. Another important factor is the colors in the graphic tees, for example if you are wearing blue jeans then your graphic should have a complementary color in it. Last but not least your graphic tees should help make you stand out. You want to wear something that is unique, because there is nothing more embarrassing than going to a party and seeing someone wearing the same graphic tees as yourself. A good place to find a graphic tees is on the web at a web site called urbanmist.com.