One of the downsides of moving around is not having a dress form. I had a duct tape one in California, but there was no way I could move it to Australia, and now the Netherlands. So I've been doing without for three years. Mostly I do okay, Dan is some help, but I really needed some sort of form to create my Steampunk outfit. Especially the bustle. So I came up with the following:
Start with a rather weird plant stand that already exists in your apartment.
Take out the glass thingy and stick your yoga mat in it. Tie some ribbon around the bottom of the mat to keep it at the height you want.
Wrap some random fabric around the mat and stand to pad the metal bar a bit. *Feel free to omit this step; it doesn't really help with anything.
Tie some lumpy couch pillows around the fabric with more ribbon.
Fit your corset around the pillows and adjust your laces to your measurements. Aim to have the waist height of the dress form be approximately your height.
Use dress form to fit bustle.
I hope you all have options that are at least as good!