An old dress from a thrift store stained with tea to look old and ripped and shredded a bit too, maybe add fake blood. If you get bored you could roll it around in mud and make it look like you were buried alive.
I'm Being An Evil Doll For Halloween, What Should I Wear?
Wear a dress like Dorthy's on wizard of oz but add rips to it ,also add loads of black eyeshadow and eyeliner paint big red circles on each cheek but with fake blood and let it drip,drip,drip also paint your face white hope this helps
Hmmm Maybe Like a wig... Some face paint bloody axe.. Bloody dress.. And fake blood
A black dress not to long church shoes and white stockings
You could always buy a different costume (since there aren't that many evil doll costumes) then you could cut it or tweak it. There are some great Halloween costumes that might work for you on summitfashions.com. But like you said, focus on the costumes accessories, they will make or break the outfit.
What about putting on a facepack. Blow dry with a hairdryer and let it crack to give the impression of an old doll. :)
Wear lotsa black n ripped jeans(black) for the final effect!