The first lesson I received on sewing when I was 10 yrs old was to pre-wash your fabric to prevent shrinkage when you have completed your project.
Every time I purchase new yardage, I throw it in the washer on the gentle cycle with mild detergent and then into the dryer. I then hang it over the banister overnight to ensure it is completely dry before folding it and adding to my stash. I only iron it when I am ready to use it. If you iron before,fold and store it, you just have to iron it again when you are ready to use it and who wants to iron yards of fabric twice. Definitely not me!
Another quilter shares their thoughts on pre-washing here. I think that I should stick to the first rule I received on sewing. I would be devastated after spending all that time making a quilt to have it ruined.
I have also read many individuals attempts on machine washing charm packs and jelly rolls. Some with success, some without. I will not machine wash them as they will fray like crazy however, I do plan on hand washing them in the kitchen sink using woolite and hang them to dry over the banister. My motto is better to be safe than sorry.
What tips and tricks have you discovered along your way when pre-fabric? I welcome any suggestions.