I did the edges of a scarf in seed stitch and what I did gave it a very nice edge.
Slip the first stitch in every row as if to purl. If the next stitch is supposed to be a knit, bring your yarn around under the right needle to knit it.
If the next stitch is supposed to be a purl, bring the yarn around under your right needle and then between the needles to purl it, rather than just purling it from the front.
I also knit the last stitch in every row.
You can add two to the total stitches, depending on how wide you want it to be, but they don't count in the stitch pattern count.