I know that your eridan tutorial was ages ago, but I have a question: Why did you make the cape an collar separate and attached them to each other, while the cape's top and collar's bottom measurements match?
Ahhh.... Good point D:
Intetionally, I did it because I figured it was it was an easier way to deal with putting the interfacing inside the collar. It didn't seem like much for me to then just attach it. However..... all the turns you gotta make to sew the concave parts and whatnot in the collar, it seemed too much fabric to try and maneuver under the limited space under the sewing machine? Like if it were all one big piece, I can imagine all this weight of fabric I'd have to pull in and around... well for me anyway, I just thought it was more efficient to do it in two pieces - one Big Squarish piece and one Smaller More Fiddly piece.. Perhaps efficiency for you could be to do it all in one piece, if you don't mind sewing all in one go around the edge of the entire cape's shape, and can handle passing through all that fabric under that machine and still do the finicky turnarounds!
Either way, hey, I guess my method could do some revision, unless you or anyone out there is interested in giving a crack at it, I really don't mind :P