For a small wrist (shown), cut 2 pieces of leather each 5" long. For a standard men's bracelet, cut 2 pieces each 6" long. or measure the wrist size you want, add 4" (for the riveted overlap portions), and divide in half.
Adjust rotary punch to 2.5mm.
Wrap one end of the leather strap around the centerpiece, overlapping leather by approximately 1". This gives you room to safely set the rivet without hitting the gemstone or crystal centerpiece, or riveting too close to the end of the leather.
Mark the spot to punch, keeping the leather overlapped and lined up nicely. Carefully center the rotary punch and punch through both layers at once.
Place a 2-part rivet through holes, making sure domed head is at front of bracelet. Place domed head on rubber block, place rivet setter on back of rivet, and hammer firmly. (Using the rivet setter on the back-side like this, prevents marring the front of the leather. The rubber block prevents flattening the domed rivet head.)
Repeat with other piece of leather.
Add the clasp to one end, overlapping the leather by 0.75 - 1".
Repeat at other end of bracelet, but simply make a loop of leather the same size you used for the the clasp.