For this project, I used the same increases and decreases as I did in the Sophie Hood.

For the first increase, I used a backward loop cast-on between the i-cord edges instead of working a kfb into the third stitch. This adds a new stitch with a small bump that mimics the look of garter stitch and sits neatly between the two i-cord edges. It keeps the edge stitches undisturbed and prevents that stretched-out look.

After that, I worked all further increases as a kfb in the first stitch right after the i-cord edge. Keeping the increase one stitch away from the edge means the i-cord itself remains nice and even, while the scarf grows wider row by row.

For the decreases, I switched the SKP (or SSK) to a k2tog. In garter stitch, I find this gives a smoother, less fussy shaping line. The edge flows more nicely into the rest of the fabric.

At the very end, I worked the last decrease like this: knit the first two i-cord stitches, then k2tog over the third and fourth stitch. This brought me back to 6 stitches to work the final rows.

Overall, I am really happy with how these little tweaks tidied up the edge. I uploaded some pictures if you want to have a closer look.