After trimming, the seam allowance needs to be ironing out to set the stitching and make it easier to turn the collar so that it is right side out. By the way, the correct way to hold the point turner is to hold the turner with the curved side down in the palm of the hand. The thumb slips inside the collar and point of the turner applied to the point of the collar. In one clean twist (like shucking clams), the point is turned out on each end. There will always be a ball of fabric in the tip. I've found I can 'walk out' the extra fabric by rolling it between two fingers while the point turner is inside. Care must be exercised to keep the point turner from poking through the tip .. a very evil thing.
Here's my almost finished collar on both inner and outer (seamed) sides
The final steps are to edge stitch the collar. It's a little tricky at the tip. To keep the pressure even on the presser foot, I slip the opposite end of the collar under the rear of the presser foot.
Then I flip the collar up, iron it out, and slip the collar bottom tips inside the stand.
You can see the seam is now facing out. The outer stand is now tucked in 5/8" and then edge stitched from the center out. I didn't quite like the way it was turning out. I should have left well enough alone, but I razor cut my seams, tried to reset them, and made something of a mess.
Here is the finished collar. I've got the Bill Blass collar and stand on a Simplicity shirt body. This is the first time I've sewed linen and I have to say the fabric has a mind of its own. Maybe when one spends more than $4/yard for linen, it's more compliant. Next, I'll tackle the sleeve plackets. G'night.