This glow-in-the-dark pouch is made with CoolGlowStuff.com 3/32" glow cord. I used about 16 feet of cord, 1 ft for the cinch cord with cord lock and 15 feet for the pouch using half hitching/needle hitching for the knotwork.
I tied the pouch around the Gerber Infinity Ultra LED flashlight with a #1 sized S-BINER, but it would also fit something like a similarly sized pocket knife.
Whatever you tie it around needs to be slightly larger than the object you'll store in it when used for a pouch. This makes it easier to insert/remove the object. Different sized sections of PVC pipe make good mandrels for knot work. Paracord is great for pouches too, but on a smaller object like the flashlight, it might seem overly thick for what's inside(YMMV).