I am the world's laziest quilter. I have a theory that the easiest way is the best way for me. Most of the time when I am spraying starch, it's prior to layout and cutting therefore, it's usually a decent sized piece of fabric. I like spraying on the top just because I like the feel of a smooth fabric -- doesn't have to be the top, I just like it. I spray what's on the board and what's hanging down. By the time I get to the bottom, the top is about right for ironing w/o flakes. I don't soak it, usually that's not needed. I don't spray and dry it -- that's just another step. Keep It Simple is a great motto.
After ironing, I have another trick for keeping the fabric neat. I put the heavy cardboard rolls from wax paper, plastic wrap or tinfoil over the round cardboard on hangers for pants from the cleaners (release one end, pop on the larger cardboard and replace.) With this large round cover, the fabric doesn't crease as it hangs around waiting for me to use it.
Kay