So, to avoid some of last night's fiasco, I do some rough drafts of templates on copier paper to help get a visual of the build/components. Once I was happy with that, time to make my templates from Poster Board.
Bottom left outline is the outer most layer of leather for this sheath. I label the template "Finish Side" or "Rough Side" so I won't mess up and put the template down incorrectly. The rectangular protrusion will be a loop (sewn to itself, around the welt/back layer) to hold a ferro rod.
Middle right outline is the inner most layer of leather (closest to the hip, or the back of the sheath). The strap coming out from this piece will be the retention strap, coming around the handle and fastening to a "Sam Browne" button on the face (outer layer) of the sheath. This will be trimmed to fit later.
Upper left outline is the middle layer, which includes the "welt". The welt will define the internal space thickness for the sheath, to fit the blade. The blade profile is traced out, and will be removed. Since this is a clip point blade, the size of the opening for the blade to enter/exit the sheath must accommodate the largest width point of the blade, this is verified while tracing the outline of the blade on the welt layer.
Normally, you will see the belt loop portion of the sheath to be a part of the back layer of leather, and, as a result, after being folded over, you see the flesh side (suede) of the leather from the front, rather than seeing the finish side (smooth) of the leather. Here, I'm making the belt loop flap as part of the welt layer, allowing me to keep the finished side of leather visible from both sides of the knife, as well as the folded over belt loop.
The center portion of the welt layer will be cut out. Roughly 1/4" of size is added all the way around the blade for this style of knife, to allow for the welt to be glued/sandwiched between the two halves. It will then be stitched. If this were a drop point blade, one piece of leather folded over would work, and a simple strip of welt sandwiched between the two edges. But, the upward sweep of a clip point blade can (as Blake well knows) cut through the leather. So, a full perimeter welt protects the sheath from damage when inserting the knife.
With the templates cut out, I make a reference where I will "Skive" the leather on the welt layer. Skiving, is to shave the surface from a starting point (full thickness) to an edge... creating a wedge shape. Between the welt edges, this middle layer gets skived, and will be cemented to the inside face of the back layer of the sheath.
You can also see that the Outer layer of leather isn't as tall as the sheath's body for the welt layer and back side layer. This is because the scales (handle) will rest on the flat of the outer layer of the sheath. And, since the welt layer will have finished side of leather facing outward, and will be cemented to the inner face of the back side of the leather, only the smooth/finished face of leather will be visible when the knife is out of the sheath. Also, having leather sitting above the point of the scales resting point, allows for protection of the wearer from getting poked with a tip when sheathing the knife.
For orientation purposes, the far right piece gets stacked on top of the middle piece. The two then get stacked on top of the far left piece. Since Blake has chosen it to be "blade forward" while worn on the right hip, the belt loop flap gets folded back to create the loop. It'll get secured to the back side of the sheath with a pair of "Line 24 Snaps" since Blake wants to don/remove the sheath without having to undo his belt.
With the pattern for each component traced onto the leather, it's time to lay blade to leather. Having labeled the templates, it helps to ensure they're correctly laid onto the leather, so you end up with finish side and rough side oriented correctly.