I use liquid store bought starch with equal parts starch and water in a sprayer. I spray the fabric I'm going to use and then roll it and put it in a plastic bag to let it rest and the starch to be absorbed into the fibers. I then press it. By doing this I don't have any flakes or residue on my iron or board.
I like to starch if I'm going to have bias edges or narrow strips. I find there is less distortion this way.