I just picked dark blue fabric, I think it's cotton bottom-weight? I didn't really paid attention to what I bought. Some fabric that's not too thin, have enough weight, and not wrinkle easily would be good. That way, you don't even need to make the lining for the coat. For the hat, I made a base shape out of hard-ish paper. And I sew four pieces of fabric to make the hat.(I used fabric tape to secure the fabric part of the hat to the paper part inside the hat) If you take a close look at the hat, you'll see the seams, and that will give you idea on how to construct the pattern for it. It's pretty simple. When I made this cosplay, I was pretty much a noob at sewing and I didn't keep many records of the process. Hope this was helpful though.
Ah!, so the "hardish paper" gives it its shape and you just crafted around that, right? If one were to look inside your hat, would the hardish paper be visible or is it covered by the fabric in some way?
Yeah, the hard-ish paper would be visible when you look inside the hat. I basically made the fabric part a little longer on each side than the actual base hat. So I can fold the extra fabric inside and tape it to the paper.