This is a costume I mad a few years back for my daughter and she was able to wear two years in a row (not that she was happy about that!
It was actually very easy! I used an old dress bodice & a cheap, white sheet. I decided to gather the sleeves at the top with elastic & ran some ribbon over that.
The skirt portion has three tear drop shaped "petals" over the main skirt section and each drop has a tear drop shaped crystal hanging from it. Of course no one noticed that when she was wearing it but me! *laugh*