You will get many different response's at the end of the day I highly suggest that you experiment with a block or 2 to see what works best for you. I starch before I cut any fabric, I starch after piecing components of a block, I starch each block after its assembled, and I starch my top when its done as I am pressing the seams for the rows. I can fold a completed top and it will never crease or wrinkle. I use a lot of starch! For me, I can’t piece without it.