Striped garter stitch scarf

Here is a photo of a striped garter stitch scarf with a few different shades of blue. I like the way the colors work together. However I am having a hard time keeping the edge of the scarf fairly neat looking when I am twisting the unused yarns up the side as I work. Any suggestions?....On the other side of the photo is part of the seed stitch scarf. The seed stitch has a great organic texture to it.