I always prewash and dry flannel before messing with it. I also rip it to find the straight of grain before cutting because you can't rely on the selvage edges to find straight of grain as the fabric shrinks but the selvages don't. I also starch it fairly stiff as it likes to do the creepy crawly thing when cutting & sewing if it's not starched. Some of the good, heavy "quilter's flannel" is much better behaved but it isn't as soft & cuddly as I like flannel to be.