I'm afraid the question of whether to pre-wash or not, is ageless and has no right answer. Personally, I like to prewash my fabric, and if I can grab it before it is totally dry, then I set up the ironing board so I can watch a favorite show or movie and iron while it is still slightly damp. When I do that, the ironing doesn't seem as boring, and before long, everything is ironed, folded and ready to put into plastic totes or it goes right into a quilt.