Have you ever wondered why a poodle skirt is usually made of felt? Felt doesn't fray and therefor you don't have to hem it. If you do try to hem a circle skirt, like a poodle skirt, you will discover that a deep hem is going to be a nightmare to get the hem facing (the inside of the hem) to lie smooth... because it is so much wider than the area that the hem will get sewn in place. Looking at the illustration, the outer edge gets wider the further out you go.... so the deeper you try to make the hem, the more you have that will need to be eased in, in order for that hem to lay flat.
Looking at this issue, it makes me relieved that we can "break the rules". The rule of thumb was always to have a 2" hem so the garment would hang nicely. A two inch hem in something like a circle skirt is not going to lay nicely and will prevent the skirt from hanging properly. If the fabric has plenty of body on it's own, a rolled hem may be sufficient. A fabric such as felt or Polar Fleece will not need any hemming. A woven fabric will need some kind of hem. The looser the fabric weave, the easier it will be to ease in the fabric of the hem to make it fit without any tucks or gathers.
A simple sewing process makes it possible to ease in the fabric threads to make the hem fit in the desired location.