Yep, thats what I’m struggling with (sorry, probably could’ve explain better). The modelling itself isn’t a problem -its knowing what to model (and how to animate it). I can’t model that baggy sleeve as it is in that concept art because the arm has to be in a lowered position. Even in a relaxed T-pose the sleeve hangs open under the arm, and I need the sleeve opening to assume a ‘tear-drop’ shape when in the arms down position (I’m guessing the answer may have something to do with vertex weights -but that’s probably what APEX is for?).
Unless someone has direct experience with this and can spare the time to explain, I’ll just play about with MD, Max and APEX and see what I can come up with.