Sprite Stitch Board!

I am making a scarf in stockinette stitch. I love how it looks with the yarn i selected.

what border stitch can i use that will keep it from rolling in?

Or are there other techniques to prevent this?

stockinette stitch?? I'm not sure what that is. Is it tunisian crochet?? If it is then I suggest you just put your hook through the front loop only. That way it won't curl as much. Blocking it afterwards will help too.
This is all dependent on whether I know what your talking about though I'm currently working on a tunisian crochet cowl.