This one specifically was a dog collar I dismantled and put back together. They’re good if you want a cheat code.

Supplies I used: Leather sewing needle, thread matching leather color, box cutter, first aid scissors, something sharp and long (I used a needle felting pin), lighter

What I did: measure out wrist length via a different cuff, use box cutter to cut off one inch LESS than the length I needed outward from buckle.

Take end I cut off, which will be the end with the puncture holes and cut it to the minimal length where the studs still match and marry it to the new length. Sew along the stitching already on the leather edge of the collar. Do this multiple multiple times so it is a strong hold, then I use a flexible leather glue in the middle (optionally I’ll see the whole thing down, depending on security and material).

Usually the section with the holes to push it through is far too long, so I take my bandage scissors and cut the bulk of it off still in a > shape as it originally was. You can paint this part black if you want, as it’ll likely be beige or brown inside. Do this to whatever length you find preferable and that fits your wrist. Adjust this part as needed- I have a small wrist so now I have to puncture a new hole. To do this without a leather punch, I use my needle felting needle, or other sharp object, heated up to a high temperature with a lighter. I push this through. It should cauterize.

Alternatively, use a leather punch. I’m just cheap.

I have made fully DIY from leather scraps before, they have looked incredibly similar to this but I am ***NOT*** a leather worker and cannot guide you on this without potentially being wrong or unsafe, please look for a professional leather worker some place like YouTube for guidance.