This is basically the same pattern I use for all of DH's shirts. (You can see more in the Shirts gallery.)

I made changes to this pattern to make it more pajama-like. No cuffs, and piped bands instead. Piping on the placket and pocket edge. No interfacing in collar or stand, for comfort. All seams in both pieces are either enclosed or serged and topstitched down for security. Larger and fewer buttons than a regular shirt.