I do it with materials.  If I was doing a dress I'd divide into 3 mat groups Top, Skirt and Waist.  The waist mat group is like a belt between the top of the skirt and the bottom of the top (:?).  Depending on the garment I make it from make it as wide as is necessary.  But if it's a dress I usually make it one poly thick.

it's easy then to add the Waist Mat group to the constrained group to keep the skirt part from slipping too far.

With a bit of work you can also use that Wait Material as one of the Dynamic groups, then set the cloth properties on that group to act like an almost elasticated strip, or at least a piece of cloth that does not deform too much so it stays more or less where it should be.  This can avoid bunching issues around the waist during the simulation.

John.

Fugazi (without the aid of a safety net)

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