Liz from Cotton & Curls shows how to make a boxy top that buttons up the back. The shape is simple and easy to draft, especially if you have a boxy top already that you can use as a guide. The buttons are purely decorative; the neck is wide enough that you can slide the top on without having to unbutton. If you wanted a higher neckline, you could adapt the back seam to be a functional button placket. Get the tute.
[photo from Cotton & Curls]