the best "base" for costume making is a graduation gown!  mine is black (this year) and i made a little bib thingy with some white eyelet ruffle sewn on a scrap of interfacing.  guess which supreme court justice i'm going to be??  if you get a red gown, be a devil.  if you get a green gown, glue on leaves and be a plant!  there's no end to this method!