When I cast on for the Dovetail Pullover I began with the front. Why? Well, I was determined to make a V-neck, rather than the ribbed boatneck shown in the pattern. The boatneck looked tricky to execute and not at all flattering. If the V-neck didn't work that would be the end of Dovetail. No back, no sleeves, just rip and start something else.
I think it's working out. See --
I haven't completely finished the front, just took it along far enough to be sure that the neckline would be okay. I don't typically plan or design anything, or (heaven forfend) make a drawing or chart; it's more a process of coming up with a vague idea and then noodling around to see what works.
Comparing the knitted piece with a V-neck pullover that fits well, I got to a point where it seemed a good idea to start the vee. I knit each of the two middle purl stitches together with the traveling knit stitch to its right (or left, depending) and then did a K2tog or SSK on every right side row. This follows the way the cables were developing, but has a different slope, since the edge is only moving over one stitch at a time instead of two. It would be nice to be able to decrease all the way over until the edge of the vee meets the side of the cable section, but that might make the shoulders too narrow. Time will tell.
For now, the front looks good enough that I have embarked on the back. It's coming along nicely too. Sort of like knitting the second sock – all the decisions have been made (exactly where to place the waist shaping, when to start the armholes, etc.) so the knitting is completely mechanical . . . and very restful.