I just finished getting a few of our outdoor decorations up. I mostly needed to see what we had so we could decide what we wanted to get to decorate for the party. I put my old witches costume on my dress form along with my black cape. I used the plastic darth vader helmet from my son's old costume as the head (I put it on backwards so it is just solid black, no detail) and put the hood of the cape over it. That is currently sitting in my entry, but will be moved to the garage for the "haunted garage" thing.
I have another wire frame dress form that has an antique wedding dress on it. I'm going to find a scary, ghostie kind of mask for that and put it in the garage for the party as well.
I still have to go and get the other pattern for my costume as well as the material. With what I'm going to have to pay for all of that and what I just ordered (costumes for the boys as well as a few decorations), I will have spent way more than I really intended to.