ManneqArt, who focuses on bringing Wearable Art to the attention of the American public, has issued their call for entries for the 2013 ManneqArt competition. The early deadline is March 30, 2013. There are various competition themes.
The best starting point is to check out the ManneqArt competition general rules and move throughout the ManneqArt website from there to get a better handle on the contest requirments. Good luck!