Use Button-band pick up for vertical edge, use this method along BO or CO edges, such as center Front and Back of pullover.
Use a skinny circular needle (I prefer a size US 0 / 2 mm 40" [100 cm] circular needle) to pick up stitches around a neckline. First pick up the stitches as described. Then count your stitches and figure out if you need to add or subtract stitches to reach the stitch count given in the pattern. Now join yarn and knit one row on right side off of your skinny needle and onto your called-for needle size. As you knit, pick up or knit together stitches to obtain correct stitch count. Begin any pattern stitch on the next/wrong side row or round.