Alrighty folks!
The mods here have been seeing a lot of people cosplaying female characters (and some male i.e. the young Italy brothers) in their dresses without a petticoat. This can make a nice dress look a little dull and lifeless. Using petticoats really adds a nice poof and shape to a dress!

It’d be a bit hard to achieve her Children’s Day poof without a petti!
As for hoop skirts—be careful! When you wear hoop skirts throw a petti or crinoline over it to hide the hoops in the skirt (it can be a bit distracting when you see those) and it’ll give your dress a smoother shape.
>YES YES YES 100% YES looking for a belarus costume back in 2010, NONE had poofs. So I made my own damn costume and it...