I got this Eagle Creek eyewear case a few years back. (It’s slightly different than the one pictured here, but close enough.)
No complaints about it all. It did have a silly velcro arrangment on the back that I guess was meant to serve as a belt loop thingy. Didn’t think much of it, but I do think a lot of PALS. Figured I’d retroﬁt it to be be compatible with all my other modular gear.
I always just use scraps of webbing I have around. No sense cutting up a long piece, if a smaller piece will work. I tend to like the look of various shades of OD. A bit of a trademark.
At the seam side, I just opened the seam, clamped the webbing in and sewed it in place. At the other side, I just bartacked it on.