Wonder Woman tiaras are appropriate for a number of occasions, including the release of the film on home video in September. You can learn how to make the tiara now and get a jump start on viewing parties for the movie, Halloween, and life in general. Instructables user Plastic Apprentice has a tutorial for making the tiara from DIY PolyArmor or materials such as Worbla or craft foam.
The project starts with templates. Once the pieces are cut and layered, you have to add curve for the tiara to fit the head correctly:
What I did was take a scrap piece of black cloth and layed the flat tiara onto the cloth and hit it with the heat gun till it started to soften, make sure when you are heating it that you don’t stay on any one spot too long, try to heat it all evenly. Then you can lift it up by the cloth and layback, carefully placing it on your forehead and gently curving the sides around your head. Be careful, as it is warm, the cloth will create a slight buffer but still be careful.
Get complete details at Instructables.