Here's the back box pleat with its centered stripe. When it comes to shirts, it's all about the little details. They can be fun or they can make me want to scream. This is my third version of this shirt and I learn something each time. Mostly, I try to make things as easy as possible for myself. I concentrate most of my efforts in cutting out the pieces. For example I set the stripe of the back yoke well in from the seam. This helps preserve the effect that it's sewn straight (which it probably isn't!) If a stripe had ended up on the seam, all my cutting and sewing imperfections would be magnified. I also did the same thing with the collar and cuffs.
I hope this has been helpful. Next time I'll show the finished product.