The clothing pieces were the easiest for me because I have a custom "sloper" (or dress block) pattern. I would highly recommend either having one commissioned or making one if you plan to do much costume making, once you have the sloper it can be modified to make just about anything.
Aside from the shoes, I also didn't make the belt, I enlisted help of a friend who's amazing with leather who used a pattern found online. Same with the wristcuff, I did make it, but used a simple tutorial from the same site. Also gotta give credit to the internet for the staff, I modified a very popular tutorial that uses simple hardware store parts, and used a textured spray paint instead of matte.
For the under shirt, I decided on a raglan sleeved tunic, cut short at the waist and low at the top so I wouldn't have to worry about extra bulk. I used a sample fabric that I had test dyed for the outer shirt, which is why it's so uneven. It's a pretty standard shirt-weight cotton fabric, and feels great against my skin. I believe the actual undershirt has a few seams across the sleeve that mine lacks, but that would be a pretty simple addition by adding width to the shoulder/sleeve pieces and creating the seams before attaching to the bodice.
As for the main shirt, I decided on a lighter weight cotton. I cut the shoulders in toward the neck quite a bit, and although I don't think the original has a shoulder seam, I went ahead and created mine with a shoulder seam because it's easier and is hidden under the wrap anyway. I used a single-wide bias tape to face the neckline, and hand stitched it down on the outside of the tunic. I did this rather than creating a separate facing and then adding bias tape on top of that because I really like the lightweight look having just the tape gives. An actual facing would have added bulk.
The pants are simple harem pants that I gathered and cuffed just below the knee. The fabric is an amazing poly/rayon blend I found on clearance at Hancock Fabrics, I am using the 'back' side, it has a shiny metallic thread that runs through the 'front'... I self lined the pants to give them a little more structure, and chose to go without a waistband, instead they have a side zipper like a dress slack. And like all my actual dress slacks, yes, I know I need to iron these =P but I figure the wrinkles give it character!
On the cuff of each pant leg, I left the side seam open and attached bias strips made from the same fabric for the leg wraps. I made the strips long enough to wrap about 3 times around each leg. In most of the film she wears the wraps around the cuff, but I can also wrap it down around my legs like she does in a few scenes. Without tacking down the strips though it's not practical to wear the wraps this way as they slip down easily thanks to the slippery polyester fabric.
I wanted this costume to be as simple to wear as possible, so I decided to create arm wraps that would not come un-wrapped. I created a regular sleeve (of the same fabric as my inner shirt, but obviously this can be any fabric, since it will be covered) and then wrapped strips of cotton gauze fabric around it. I measured 3" strips from a section of gauze fabric and then 'snip and ripped' to create a nice raw edge that will not fray much. I hand tacked the strips down once I liked the wrap, leaving the last few inches un-tacked so that I can tighten it to my wrist. I left enough extra so that once it is wrapped, I just tuck the extra under and it stays nicely.
The last fabric piece is the tunic/tabbards/dress... It's just a simple rectangle, gathered at the shoulders on each arm. I also added small snaps at each of the shoulders so that everything stays put. I used a semi sheer polyester blend, the weight is great and it slows really well. I cut the width (60") down the middle to give the final width, leaving the non-selvage edges raw. The length is made from these two pieces and has a french seam at the middle (to prevent fraying).
After everything was completed, I weathered the whole thing with a variety of different materials. Mostly dye, shoe polish and makeup. I wanted the stains and weathering to withstand washing, and also to be sanitary so I can take it to places like Children's Hospitals without any worries. After seeing the movie a few times, I think I'll be making more stains and darkening the weathering, but for now I'm pretty happy with how it turned out! And, of course, Rey is such an incredible character to play, and having a comfortable costume certainly helps!