Well, typically you'll want to give the simulation a few frames at the end to let the cloth settle. If your model is still posing and morphing when the simulation ends the cloth may not look all that natural.

But back to the OP. The main thing is to make sure there is no poke thru at frame 1, and usually the easiest way to do that is to take RedPhantom's approach.

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OS: Windows 10 64-bit, Poser: 10