For a little more detail, I use seam-stick rather than pins. Since seam-stick tends to gum-up the needle, it is applied toward the center of the hem away from the stitch line. The inside, flat-feeled seam is the hardest to get over, so I start toward the back on top of that seam, sew a few stitches, back-tack and then sew off that hump rather than over it. Starting on that seam also means that the starting and ending back-tacks are less visible. The regular seam on the other side is relatively easy to get over. The jean-a-ma-jig is helpful finishing on the flat-felled seam.