In this method you attach the outer collar stand to the shirt by itself, then attach the collar to that, and then sew on the inner collar stand.
Step 1. Make the collar
Step 2. Prepare the neckline.Stay stitch the neckline of the shirt and clip curves.
Step 3. Attach the outer collar stand.With RS together, pin the outer collar stand to the shirt neckline, matching cnetres and notches. The ends of the collar stand should protrude from the front edges of the shirt by the given seam allowance. Stitch the seam, trim SAs and press up.
Step 4. Attach the collar.Baste the collar to the outer collar stand, RS together.
Step 5. Attach the inner collar stand.Press up the SA of the inner collar stand and baste the folded edge over the seam.
Attach the inner collar stand, RS together, matching centres and edges. Trim the SA and clip the curve. Turn right side out and press.