I think it refers to the way a piece of clothing "hangs" on the body, i.e. without forming ugly folds or so - i.e. it fits nicely. Specifically, I don't think "fall" refers to some type of part, design or pattern. Cf.
http://images.google.com.ar/images?hl=es&q="med vackert fall...
I notice that Norstedts engelska ordbok proposes the translation "graceful hang (fall)" for "vackert fall" and they offer the example sentence "Kjolen har ett vackert fall." But perhaps this is just a too literal translation.
The translation workplace 
peer agreement (net): +2
