I'm fortunate to have a sink down in my sewing room so I hang my fabrics up over the sink and spray away, let dry and then iron. I spray on the wrong side and iron on the right side so no flakes. If I'm in a hurry like yesterday I will spray right there on my ironing board but I try to overlap my fabrics so not as much will fall on the ironing board itself. Still spray on the wrong side, let it set 5-10 minutes and then come back to iron.
I try to estimate how much of each fabric I'll need with a little overlap in case of miss cuts, then spray everything at one time and let it hang over the sink to drip if that's the case. I make my own starch mixture using the vodka method with added liquid starch as I like a crisp texture.