I started off just knitting a random garter and stockinette top-down shawl triangle in fingering weight yarn. The yarn is Lion Brand Sock-Ease in the Taffy colorway. As the triangle grew, I decided that I wanted to finish it with the lace in-the-round portion of the Caedwyn Cowlette, so I knit the triangle until it had 158 stitches on each side (which is double the stitch count of the Caedwyn pattern for worsted weight yarn) to set up a base for the lace.
So the top of this cowlette does not follow Corrina's pattern, but the bottom lace portion does.
I don't remember the details now, but I seem to recall having to add a stitch or two in the first row of the lace to get the stitch count to come out right.
In addition to the stitch marker that shows the beginning of the round, I found it helpful to also place stitch markers on either side of the shape that grows out from the bottom front point of the cowlette (you will see where those stitches begin and end in the pattern instructions)