Wanna in El Paso wrote this explanation for draping fabrics.
If I want something to look as if it's been tossed aside after being worn, I first cover the bed, chair, or whatever with plastic wrap to protect it, and/or to make the garment more easily removable later.
Then I either spritz the dress lightly with water, hair spray or fabric stiffener, depending on the fabric or what I have on hand. Some people use steam from a steam iron. ( If I am working with silk, I hesitate to spray unless I dampen the entire thing because silk spots so easily.)
Another consideration is whether the garment has been sewn or glued; if sewn, it's less of a concern; saturating a pieces that has been glued may affect the seams. Whatever is used, the idea is to make the garment malleable so that the natural folds and wrinkles that come from gravity can be manipulated. (It helps to toss a real dress on a real bed and see how it actually looks; sometimes I Google for images, as well.)
Sometimes I pin the folds where needed first, then spray. On occasion I have taped the folds lightly with either masking or cellophane tape, sometimes tied with string until dry. It all depends on how easily the fabric can be shaped and whether the object on which the garment is tossed is hard or will receive pins.
Then I let dry, remove the plastic wrap, then replace the garment, using just enough glue to hold it in place, in case I want to remove it later without messing up the surface. When I am placing a garment atop something special, like a hand-made quilt, for example, I don't glue; I figure out how to pin underneath the folds to hold it. Sequin pins are good for this because they are so tiny.
There are numerous draped items on my website.
Here is an example of a throw that has been manipulated on a hard wooden surface:
http://wannainelpas o.com/seasons/ irenes_christmas _bench.shtml
Here is Santa's clothing manipulated on a wooden screen, as well as over the arm of his chair:
http://wannainelpas o.com/seasons/ santas_nap. shtml
And here I discussed making his clothing, too:
http://wannainelpas o.com/dolls/ napping_santa. shtml
The first dress I remember trying to manipulate in this way was actually on the doll. I wanted my Wife of Bath to look as if she had just collapsed on her bed after the long tiring journey home from Canterbury. I had a terrible time with it because I wanted her to look natural, rather than just balanced atop the bed, and since I had already made her completely dressed I had to - gasp - cut away the fabric at the back until I could make it look as if her body was actually somewhat sinking into the bed coverings the way our bodies do naturally.? I wound up cutting and cutting away, finallly poking glue up inside the folds and pinning them in place until they dried. If I were to do her nowadays, I wouldn't even make an entire dress, I would just do the bodice front and drape fabric around her to make it look like it was the skirt.
You can see what I am talking about here:
http://wannainelpas o.com/The% 20Wife%20of% 20Bath/the_ wife_of_bath. shtml
