This simple modification to a Mora knife sheath (Companion HD) to prevent the knife from falling out was sent to me by one of our students, Dave, and is absolutely brilliant. Thanks for sharing.
“For the bottom tie I pushed an inverted “V” of thin copper electrical wire up the drainage hole until it was visible at the top. Then I tied a loop of army “comms cord” through the V with a thumb knot and retracted the wire, leaving the thumb knot inside the sheath but the loop outside. A second loop & thumb knot keeps it in place. (Paracord is too thick for the drainage hole as is.) I can now tie it on, tie it to belt pouches with similar loops, or run a cord/strap round my leg.
For the elastic retaining loop I drilled two parallel lines of small holes at the top, cut out the joins with a chisel-bladed craft knife and smoothed the edges with a strip of wet’n’dry sandpaper. I used a small file to poke the sandpaper out one side so I could use it, and later to poke the elastic back out through the second slot. Sewed two rows in the elastic, one row to hold the knife tight and the second to form a nice tab to pull on. The elastic ends were molten with a match to prevent fraying.”