I also need to ask - what do you do if you are making things that are not your size OR you feel that you'll put the buyer off by your non-modal looks? I may make a size 10 skirt, and no one wants to see me trying to squish myself in that....
I could hold it up against myself (minus my face), I guess? So you get to judge how an item is to be worn if it's complicated. Surely, though, dimensions and sensible item description would suffice, with varied pictures to show the detail of the garment. Perhaps, if ones drawing skills were up to scratch, a little fashion-illustration-esk sketch of how an item should look?
Regardless, and if I were to wear an item to model it, I would certainly put something along the lines of "Item modelled is not item being sold, but looks the same/similar" OR "All modelled items are washed and pressed before shipping"
Washing in non-biological and fragrance free liquid of course!
And, to throw my further two cents in to the bucket - I would post items with recycled packaging and tell people so (along with why I'm doing it). If the package looks scruffy, I'd make sure the item inside was wrapped more scrumptiously, with notes and business cards and attractive wrapping.
(Says someone who hasn't actually got an etsy account and is currently only in the planning/researching stage..... )