Our weak imaginations hold us back when creating art just from our heads, because its so hard to recall specific details of things. I try and copy a piece of art or photo directly, then create a similar piece of my own design, but with the same folds or clothing design, from memory. The next day just glance at it, and try and draw another and that will help you to memorize how some clothes look and how the folds go. eventually you start to to be able to imagine/remember the folds in your head (this did happen to me at some point but I could still use improvement haha)