IMPORTANT NOTE ABOUT THE SIZE OF MY HOOD:
The hood I started out with was already pretty big. (big hoods are the only kind that stay on my head) So now that I've added an extra 2-3 inches to that, I have about 5" from the top of my head to the top seam of my hood (if I pull the fabric up) (It usually settles in these gorgeous curves like in the picture at the very bottom. You know, gravity).
That is 10" of extra room in my hood.
This hood is so much larger than I thought it was.
comment for clarification
EDIT: Added finished picture and sorted out my math terms. (whoops haha)
EDIT: Clarified the pressing tips section and added some notes in the margins. Also, I added a small section for talking about edge stitching.
IMPORTANT EDIT: Now that we've finally seen it from the back, John's cape apparently is not this shape!! It is square, not rounded! please ignore my last few pictures shape-wise, your cape should obviously be square!!