If you're looking for a professional dressform, look for "Wolf dressforms" (wolfform.com). Mine is called a "MyDouble" dressform; it's mostly for fitting garments to your specific measurements, I've draped a few garments on it and the professional forms are definitely better! But don't stress if you can't get one or don't know anyone with one, it's definitely a big investment! The alternative for draping I'm going to show you will only require a pattern purchase, no hundreds-of-dollars dress form :)
The dress on the dressform was NOT made by me (I wish!). It's by the Japanese brand Angelic Pretty.