You can dilute white wood glue, like Elmer's glue with water and apply it with a spray bottle, on fabrics or paper, once it is absorbed and dries it will be stiff and usually will hold the form you choose. Don't over wet it, just a fine mist is best, and it may take a few applications to get the shape and texture you want. The more water you add the thinner the mix and the less holding power the mixture will have but with multiple coats enough glue will be available to hold the shapes you desire. Usually it dries clear and you don't see it but you can feel it's stiffness increase with each coat applied. Test apply to fabrics before you use your display items.
The link below describes white and wood glues and of course wants you to buy their glue.