1) You must be a @c_arabesque follower
2) Simply retweet this post: "Designer Vintage Contest going on now-3/15! Follow @c_arabesque & RT this post to win 20% off any item! http://www.couturearabesque.com/2012/03/twitter-contest-20-off-any-item-in-shop.html #twittercontest"
3) So as not to be totally obnoxious, participants can only retweet up to 3 times total and you have until midnight March 15th to do it.
I'll be drawing a name at random on 3/16 and that lucky person will receive 20% off any Couture Arabesque Vintage item of their choosing BUT you must use the discount within 24 hours!! Good luck!!