Sometimes the starting row on this scarf is looser than the rest of the rows. To tighten it up, I have done one of two things (or both, if needed):

1) Crochet the first row with a size smaller hook than what is used on the rest of the scarf.

2) Crochet up the opposite side of that first row with the linen stitch. The stitches will be pointed in the opposite direction, but it blends in just fine. I have to really study the scarves I made thus far to even detect the different directions of the stitches. And even then, it’s a non-issue. Crocheting two rows (of alternating colors) on the opposite side of that beginning row will make it virtually impossible for you to see it.