If you don't understand some step in video all steps are written below.
Step 1: Making Template (steps Written on Images)
Lets make a sheath now
Step 2: Trace and Cut Out Pattern
Step 3: Dye
Dye both sides of leather and let it dry(note that after final wax coat colour will be much stronger)
Step 4: Make Grooves
Make groove for thread to sit flat ( you can use some smoothed nail to make similar groove if you dont have the tool but leather need to be slightly wet)
Step 5: Trace and Cut Middle Part
Step 6: Mark Glue Place
Step 7: Glue Middle Part
Sand face of the skin and put glue then let it dry and connect the parts.
Step 8: Cut Belt Loop
Wet the leather so its easier to bend then mark belt loop lenght and cut it, mark glue place,sand it and put the glue there.
Step 9: Dye Edges
While waiting for glue to dry dye the edges which will be difficult to dye later.
Step 10: Belt Loop
Connect the parts and make stiching groove on belt loop (on this side of the skin the nail method may be difficult)
Step 11: Holes and Stitch
1.Make holes (if you don't have the hole punch sharpened fork will work almost as good, i used it before i got the tools)
Step 12: Folding
1. Put the glue on marked place and middle part then let it dry.
2. Fold the sheath
Step 13: Mark Holes and Drill
1. Mark where holes will be drilled (fork is fine)
2. Drill the holes (1,5-2mm drill)
Step 14: Make Groove and Stitch
1. Make groove for stitch on other side.
Step 15: Cut Excess and Sand
Cut off excess leather and sand the edge
Step 16: Chamfer Edges
Step 17: Dye and Burn
Dye and burnish edges with wooden stick.
Step 18: Decoration
Make some decorations (on slightly wet leather).
Step 19: Forming
Wrap the knife in foil and put sheath in water for 10-20 seconds then form the sheath around the knife.
When finished let it dry for few hours.
Step 20: Dried
When dried its very stiff
Step 21: Final Coat
Now its time for final wax coat, wax coat is made of 50% wax and 50% linseed oil, heat it in pan on small flame and let it cool
Put thick layer of wax coat and use hair dryer to melt it (repeat process if needed) buff the sheath with cloth and you're done!