You can use spray starch or Best Press to stiffen your fabric and freestanding lace but why not make your own stiffening spray from leftover water-soluble stabilizer scraps?

Sulky has a great recipe for making your own fabric stiffener using leftover WSS, distilled water, and rubbing alcohol. The rubbing alcohol is an option but eliminates having to refrigerate the mixture and makes it last longer.

Any WSS scraps should work, including machine embroidery toppers.