Remove any residue with a soft dry cloth. Since it is a natural material, we can not recommend any cleaner. Aggressive cleaning agents may dry out the area or form spots on the leather. If you want to use a cleanser, please test on an inconspicuous area or, even better, on a test strip.
Thread the waxed cord through the ends of the strap and close the bracelet with a knot.
You will find many tips and tricks for laser engraving and cutting leather here.
Tips for laser processing leather