I've done crazy blocks with muslin and it works great. I suppose you could even iron it onto freezer paper cut into 8.5 x 11" pieces and run it through certain printers to print out the patterns on. Or you could do it the hard way and use a light box to trace the pattern onto the muslin. I have printed on muslin and crayon colored it in for an ABC Sesame Street baby quilt. It worked very well. In paper piecing/foundation piecing--I always square up my blocks before stitching them together so that would take care of most skewing problems. If the muslin is starched well and/or cut on the straight of grain, it should be fine.
Beverly in Missouri