I've been reading a lot about the cloth room. Have completed a few simple drapes, nothing elaborate.

What have I learned...the #1 culprit in the problems is the mesh ...double sided, overlays, and all that. The simpler the mesh, the better.

Most of the tuts and stuff I've read only use 20 frames, some even less. It appears that is enough.
The sim does not correlate to how much time it takes to get into an actual human configuration and have your pajamas fall correctly around your body....unless you;re doing an animation. In the case of stills, you just need time for the simulation to do its thing.

I have a very complicate pose rendering right now... the cloth sim is pretty much default. The one thing I see is that the cloth needs to be lighter to fold down at the knee, which you see ... also , some smoothing. but not bad for 1st attempt.

Humankind has not woven the web of life. We are but one thread within it.
Whatever we do to the web, we do to ourselves. All things are bound together.
All things connect......Chief Seattle, 1854