I wash my fabric as I use it. I put the yardage in a mesh bag and wash with a detergent that is free of dyes or frangrance (allergy free, such as Dreft) and do not use fabric softener. I use the "gentle" cycle. I take out of mesh bag, shake, and dry in dryer on the "less dry" cycle until it is almost dry. The dollar store has large zippered mesh bags that I snach up. The washer likes to have at least two mesh bags so that it's balanced. I then starch as I iron the damp yardage and then hang on the clothesline (preferrable outside in the nice weather). When totally dry I start cutting. I do set my seams as I sew. This works for me. I restarch my blocks before I put them together and restarch my backing before quilting. I also throw a color catcher into the mesh bag before washing.
Hugs!
Debbie