I don't think starch is necessary. Think about it. Every time you spray that starch the vapors are in the air and you're inhaling that stuff. Just using some steam is good enough. If you have any wrinkles you can't get out with the steam in the iron fill up a spray bottle with water and spray the fabric. I keep a spray bottle close by at all times. Works great! I read somewhere that starch helps keep bias fabrics from stretching but I don't even use it for that. If you're handling your fabrics gently and not pulling on them as they pass under the needle there should be no problem. If you haven't pre-washed it there is sizing already in your fabric. That's how the manufacturer gets it so crisp and smooth for the bolt. I never knew the reason for ironing the seams to one side other than it's difficult to get those little seams open and time consuming. It makes sense that it is done to keep the batting from working its way through the quilt top.