I love starch. I use it to "glue" layers of fabric together when I need to cut multiple units. Get the fabric thoroughly saturated with starch, layer it and iron in between layers, your fabric pieces will stick to each other as if glued. It preshrinks your fabric and I've successfully cut half square triangle and other biasy shapes out of as many as 8 layers at a time with my 60mm rotary cutter without any distortion. Saves a lot of time and you end up with nice stiff fabric which I think makes piecing easier as well.
I haven't been able to find either the liquid or the powdered starch for a while, so have been using either Niagara heavy or Faultless heavy starch in the spray cans.
Rob