I find almost everything has an effect to the cloth.  The geometry itself , what bits you make hard or soft , or choreographed, or sticky (i forget the term) , the cloth settings for weight, shear, etc all change how it drapes, then determine the pose, do you tilt it to get better drape, or fake a wind ? do you use a wind ? how many frames , how many steps per frame, offsets and collision types .. theres a lot of settings.  Then if the figure is sitting how best to get it to sit and get the cloth properly draped. Are you shrink fitting anything ?  One simulation or two or three?  it can get really complicated

 

Philc had some free settings for the cloth room that are useful. Dont know if they work in all Poser versions.