This liquid fabric stiffener by Aleene's is what I use to drape and set my miniature clothing on my dressed dolls.  It is a concentrate that I thin with water and apply.  One 8 ounce bottle.
 
"Perfect for costumes and seasonal projects, Aleene’s Fabric Stiffener & Draping Liquid offers a super strong formula that shapes and stiffens most fabrics and trims. It dries clear but can be tinted for colorful, fun effects; it can also be thinned with water for less hold. Use it for creating cheesecloth decorations, lacy lanterns and so much more. 
Heavy duty formula shapes and stiffens most fabrics
Nontoxic
Dries clear
Can be tinted with water-based acrylic paint
Can be thinned with water for less hold"