I think the easiest way to get a great finish on a neckline and armhole is to bag it out.

Not only is it the easiest, but it's really easy if you ever want to change the neckline in the future.

This technique works with any fabric, and you can use either a full lining or a facing. I don't use interfacing on my sample, but this can be added too for an even crisper finish.

In my detailed tutorial I show you how to bag out the neck first, followed by the amholes, and then how to finish your lining or facing off around the zipper.