First, interface BOTH sides of the collar stand, and the top collar. I'm using Fashion Sewing Supply's Pro Woven Fusible Light Crisp interfacing.
Next, you are going to stitch the collar stand to the shirt, right sides together, with the shirt sandwiched in between.
When you get to the shirt fronts, you want to have your needle right next to the plackets. This is where you will pivot to stitch the curve.
Roll the shirt out of the way and stitch the curve up to where the collar will attach.
Trim, clip, turn, and press. Your stand should look like this.
Construct your collar. If you trim a scant 1/8" from the collar edges (not the neck edge), you'll get a nice roll on the collar when it's worn.
Stitch the collar to the stand, putting the undercollar next to the outside stand.
Trim your seam allowance on the collar stand, turn it under, and cover the stitching from attaching the collar.
Edgestitch all the way around the collar stand. I usually start and stop at a shoulder seam.
The finished collar!