You need a really cute cardigan to go with that dress--black or white with pearl buttons. You should wear the dress to Value Village some time and try on all the sweaters.
You could probably find another blouse, but that's a lot harder.
You should also whip up an all purpose Loli skirt in a color that goes with most of your clothes. Wide-ish waistband, gathered, with a built in petticoat or false petticoat. Then you could just grab it and go, over leggings or whatever. It would be really easy to make--just boxes.