Ok I won’t be snarky.
From my experience the trick is wet. When I made pocket holsters for my keltec p32 with a j hook I hated all of them so made my own.
I personally used 91% alcohol to wet the leather then nailed the leather to a piece of plywood, then formed by hand. I used alcohol so it would not rust the weapon.
For many things you can just use water, but for a knife I’d consider alcohol also.
My option is “tightness” is not as important as consistent tight wraps. Get it wrapped “tight enough” under pulle/tie the last bit, the saturate in alcohol. The leather will shrink and then get much tighter.
Is not cut my own leather unless you have that device that cuts perfect strips.
Tandy leather still has some stores around (love them) and you can just buy it in strips like shoe laces.
I also might consider horse hide, my final pocket holsters was that. The molded side was skin side, then a flat horse hide no pronounced stitching and smooth so it just looked like a smooth pocket.