For the Natural Form dress, I decided to make hoops and a petticoat. I want the dress to have the correct look - even if the underthings are a bit off.
For the hoops, I based them off of loosely off of other natural form era hoops. Originally, I was going to do the whole belt thing - with suspenders hanging down to hold up the hoops around the hem- but it just didn't look right. So I took a rectangle of fabric and added that to get a full hoop skirt.
It still doesn't look quite right but it works. The petticoat will hide the fact it's a bit more crazy with the odd looking hoops. However, the hoops will help keep the skirt out and give it the shape it needs.
For the petticoat, I pieced together what fabric I had left over and then added some lace that I really didn't have a use for to the back of the petticoat. It's not super pretty but it is functional.