Hi retro - I use "Best Press" and I iron the pieces when they are in strips. then, when I'm done, if it's just fine, I just iron it. If it's wonky, and needs to be ironed into place, then the starch comes back out! The Best Press can be pricy though...the drawback!
I have used niagra spray starch in the past and was pretty happy with it, except when it would make flakes on the fabric. I know it goes on sale pretty regularly, so it may be more affordable.
some people make their starch with cornstarch and water. There are several threads about starch on the board you can check out too!