I prewash every fabric with a color catcher sheet and a tsp of Synthopol (a color fixative used by hand dyers) in hot water. That helps ward off the disaster of inconsistent shrinkage between various fabrics in a project as well as migrating dye. I dry in a pemanent press or delicate cycle to minimize wrinkling. That's a trick I learned from Sharyn Craig. Minimizes ironing.