I am NOT a cosplayer, and the last time I sewed was an attempt to make my brother a stuffed unicorn out of old curtains when I was ten.( I found it half-finished, thirteen years later. Last week. When doing a mass clear-out of the last few piles of things in my room, after which my dad knocked down the entire wall (he originally put it up - I had to sleep in the living room for my first month in that house!, and now they're renovating) ... uh, I've long since moved out, to clarify).
My costume analysis of Mother Gothel mainly comes from when I decided to draw her (in order to have some of my own art on the lens - I have a Thing about that :D ) - and therefore had to actually look at all the details (and decide if I could be bothered drawing the dagger, and how to best mimic the brocade without bothering to draw the actual pattern and if it should be shiny, and what colour her eyes really are, and so on).
This means that this costume description comes from the perspective of an artist, not a costumer. I've attempted to provide ideas and resources to help people get started - and more than enough to throw together a home made Halloween costume, but I do not delude myself into thinking that page is anywhere NEAR detailed enough for a serious cosplayer*
I know a little about dress patterns, wigs, and fabrics, but only what internet research will give you (I research stuff to death when I'm on a roll, but this kind of thing needs actual practical experience). Over time, as people actually create cosplays of Gothel, I'll have more information to draw on, but if you know something about this, then please:
*(... an example which IS, is my friend Bria's Rapunzel analysis - yeah, it's her fault I ever heard of Tangled, but I got her onto Squidoo, so it's probably self-inflicted. I do not like Rapunzel (PINK and airheaded and seriously ditzy - I do like the short-haired version at the end though) which may be partly why I am so fond of Mother Gothel.)