It’s probably not user error. In my experience It’s the 1.5CM(0.015M) distance under object collision and the vertex mass. Both of which work better when you scale up a human character, but work great with blankets and curtains. As for the vertex mass, I just google the cloth type and material to find it’s mass. Like “Weight of a Cotton Shirt”. Most of the time they include grams(kilograms) along with the ounces.
