First of all this is aobut the Rey main Rey costume, not the one she wears in the end scene. Secondly I'm sure that there are great tutorials out there, and builds that show how to make a decent Rey costume, I'm going to focus on the research and threads from The Replica Prop Forum and Rebel Legion.
As of now there are no finished standards for the costume in Rebel Legion, it can be submitted and accepted for membership though. It's just no clear instruction on what parts are the minimum requirements.
Rebel Legion Image Reference and standards discussion - This is the best thread for reference images. It has a lot of very detailed photos in the first posts. These are the photos you should use for references when doing the costume. Also a good tutorial for the wrist leather strap.
Rey tutorial - Dawn had the first RL approved Rey, and in this thread she and Lisa has a lot of discussions on choice of fabric and construction. Lisa is a great source, since she actually worked with the effects for the films and had access to images long before they were public.
Rey WIP thread - Puck who made this thread is from the Netherlands, so she's using materials that you can get hold of in Europe. In this thread you can also at least find patterns for the headwrap and the belt.
Rey at RPF.com - The Replica Prop Forum has a monster thread about Rey, it's 76 pages long as of today. There is a lot of information there, but some of it is wrong. Make sure that you read all of the thread, as well as the other ones in order to make correct choices.
The costume was exhibited at Celebration Anaheim and at the display there was a list of materials used
Wrap dress - viscose
Head wrap - cotton
Top - hemp and cotton jersey
Trousers - silk
Backpack - leather
Wrist cuff and belt - leather
Pouch - canvas
Arm wraps - cotton
Gloves - leather
Boots - wool and leather
Staff - 3D print
The boots have been identified and are: the "Piper V Dark Brown" boots by Po-Zu. (a UK Company)