My son's elementary school is doing a week with a different costume theme each day. I doubt that the theme is mandatory, as I can't imagine them requiring low income families to participate. That said, we would like to allow my son to dress up for each day's theme, but we have already spent a lot of money this month in preparation for Halloween. Unfortunately, the themes are specific enough that reusing our son's Halloween costume won't be an option. In fact, none of the days are "spooky"-themed or would allow for dressing up as a fictional character, so that makes it even harder.
As an example, one of the days is dress up as a historical person and another is dress up as a famous composer, but I would like the answers to be general and not focused on a particular theme.
I admit, I'm having a hard time imagining how I can avoid spending at least $20 on each day! What are some techniques that I can use to do costumes on a budget? The more I could do with things around the house, the better!