If I have ALOT of fabric to do, I soak it in 50/50 water starch mixture , squeeze it to get out excess then hang it to dry, then iron.
If I am only working with a few pieces I use spray starch. Spray it on one side of the fabric, flip the fabric over and iron on the opposite side. Once I have ironed that side dry I spray that side, flip it over and iron the opposite side again. This way I am never ironing on the side that I sprayed on. No flakes !