Unfortunately, I didn't take many pictures during the construction of the pouch, so this will just have to mostly be a verbal description of the process I followed.
When I cut the initial canvas, I should have made it wider and then trimmed off the excess on either side. I didn't realize that one of the edges (the lower edge in the photo below) wasn't straight, so when I finished with the badges and started on the device on the other side, the embroidery ran up to the edge of the fabric. This ended up meaning there wasn't enough fabric for a seam allowance along that edge.
I decided I wanted to line the pouch, so that sliding my phone into and out of the pouch wouldn't snag on the back side of the stitching. I cut the lining to match the size and shape of the outer shell of the pouch, and, with right sides together, I sewed along both short sides. Then, I turned it right sides out and sewed down both long sides close to the edges.
Since the lack of seam allowance meant there wasn't a way to have the edges turned under, I decided to just fold the pouch in half and use my serger to sew down both sides, binding the edges.
To cover the edges I used tablet weaving to create a flat braid that could be wrapped around the sides. The braid was woven using 12 cards, which were split into two packs of six in the middle section of the braid to create two narrower braids for either side of the opening at the top. As I wove I periodically held the braid to the pouch to determine the lengths needed.
The braid was wrapped around the edge of one side from the bottom to the top and tacked down. Then the two split braids were tacked down across each side of the opening.
Finally the rejoined braid was wrapped around the edge of the other side from top to bottom. The strings were left on both ends to form tassels.
I wasn't sure what to use to make the turk's head knots, but I knew it would be easier if I used a thicker cord so I could do fewer passes, rather than a finer cord which would require more passes. So, on a lark, I decided to weave a five-loop fingerloop braid out of some size 5 cotton variegated craft cord I had lying around. It looked similar to the photo below, only purple/blue.
Then I used the braid to weave a simple, 5 lead, 4 bight turk's head knot using Edyth Miller's excellent blog here:
https://edythmiller.blogspot.com/2014/11/tying-turk-head-knot.html
Once I had the basic knot created, I slid it on to the tassel and gradually tightened it down. This took a couple of tries because it's easy to go too fast and destroy the shape of the knot.
Once I had the two knots tightened how I wanted them, I tacked them in place, just to make sure they wouldn't slide back off. And that was the last step!