Purple is a great base to use, a purple net tutu with purple stripey tights.
Top with a black witch hat, decorate it with lots of tulle or lace. (a veil would be nice)
A black bodice, corset or tee shirt in black or purple (rip fabric a little her and there)
Black nail varnish & Purple glitter gelle to finish)
Try a vampire look with black glitter net tutu, collapsible top hat, white make-up, blood and lots of black eyeliner..crimson lips...crypt creeper
Try layering one or two net tutus for fantastic effect, black and white, purple and red are striking!