I saturate my fabric with starch, let it dry and then press my fabric. If it is not stiff enough for what I am doing (like bias cuts), I will starch it again. Sometimes as I am pressing my blocks I will add a little more if it needs it.
Heavily starching long strips can keep them from bowing when sewing and pressing them, it keeps bias from stretching, my hex blocks did not distort at all when making OBW's.
Cutting starched fabric is easier for me too. It seems to help the fabric "stick" to the cutting mat better and my ruler grips it better too.
Starch also helps when pressing seams, they stay better and I don't have to keep pressing the same seams over and over as the blocks/quilt top progresses. It also only takes one sweep of the iron to get a seam pressed, other wise I sometimes have to go over it again which can cause distortion.
I don't think you can ever use too much starch, too little? Yes!!! :D:D:D