The bane of my existence.
I spent some time studying the shirts in DH's closet and even found one in the thrift store pile to take apart.
The summarized steps.***
1. Sew and turn collar. Topstitch.
2. Sandwich collar band to collar. The inner band has the neck seam turned up.
3. Attach outer collar band to neck.
4. Turn neck seam allowances into band and topstitch band from the inside of the shirt.
I know there are several tutorials out there, including the David Coffin tutorial, in which the band and collar is constructed in a different order, leaving the band open along the inside collar. This method involves rolling up the collar to get it out of the way of sewing. If this method works for you, then use it. I personally found it too fiddly. I don't think it is used in a factory either.
I began by cutting the collar off and opening up the band. I didn't get a picture of the second part, but this is something you can do on your own. One thing that surprised me was that the neck seam allowance was 1/2 inch. It is fairly typical for enclosed seam allowances be 1/4 inch. Even Winifred Aldrich suggests this in her pattern drafts for men.(I have the 3rd edition and this links to the 5th edition, so I don't know if this has been changed). I love Aldrich's drafting instructions and her collar/collar band instructions are interesting and different from what I have seen elsewhere. In any event, I already have a draft that just needed tweaking courtesy of Burda. Sometimes it's easier to start from scratch and sometimes not.
There were some other things I discovered, which I won't detail. It did give me pause and I should have recut my collar bands. But I already had my blouse constructed, waiting for the collar with a 1/4 inch seam allowance on the neck. This is one of those times that I decided to make do.
And here it is, mistakes and all. It doesn't look terrible, though I did have to do some dreaded trimming around the curve of the collar band. I also had that dreaded bulky wad at the shirt band/collar band join. Conventional sewing wisdom (in industry too) says that to reduce bulk, you reduce seam allowances. In industry this results in 1/4 inch seam allowances for enclosed seams. BUT in this case, I think you will get less bulk with WIDER seam allowances. I will be testing this out in my next blouse. This particular collar is staying because it is wearable.
The neck is too small. It was one area I thought I had checked early on, but obviously didn't. Not that I would wear the neck buttoned, but it should at least fit. The neck is about 3/4 inches too small. [head on desk]
***I intentionally did not specify every step. I really, truly believe that one learns more by trying and doing. I do intend to eventually show and explain each step in a different way and format. Stay tuned.