Edges Roll when stockinette stitch is used, especially on the side with scarves and along the bottom with hats and sweaters. In order to stop this it used to be that ribbing was used at the bottom of all hats and sweaters - now that times have changed fringing could be used on a sweater, seed, basket weave, or garter stitch on a hat. 5 stitch edges can be put on scarves or work an all over concentrated pattern like:- herringbone, tweed, reverse cables. Gauge swatches can help you decide.
Good Luck Gracie