Here’s what I’ve been doing for a year-and-half now and I have lots of perfect hems. I buy soft fusible tricot. Using my rotary cutter, I cut strips the width of the interfacing. I cut them however deep the hem is (1-1/4″, 1/2″, whatever). After the side seams are sewn, fuse the interfacing to the wrong side (inside) all the way around the hem so one edge is at the cut edge of the hem and the other is at the hem fold line. Then fold on that fold line and press. What a beautiful clean hem! Then hand wind a bobbin with wooly nylon and topstitch from the outside with a double needle using the garment thread on the outside and wooly nylon on the inside.
Because of the wooly nylon, you won’t get a double-needle “ridge” and the hem will stretch. Clean and beautiful!
On my sleeves, I apply the interfacing to the flat sleeve piece, before sewing underarm seam. Press the hem in before sewing seam and it will be very easy to sew the hem when you’re done. On the Crossover tunic, I sewed the seam before attaching the skirt to the bodice – much less fabric to handle.
Hope you try and like this method as much as I do.