Real vs Faux Leather
For most cosplay applications, high-quality faux leather (vinyl, PU leather) is the practical choice: easier to sew on a standard machine, available in colours that real leather isn't, cheaper, and in many applications visually indistinguishable from real leather in photography. Real leather is superior for applications requiring durability and the specific tactile and aging qualities of genuine hide — belts, sheaths, and pieces that need to survive extended heavy use.
Cutting and Marking
Mark leather on the wrong (flesh) side — permanent marks on the face side are permanent. Use a rotary cutter or sharp utility knife rather than fabric scissors — scissors leave irregular edges. Cut cleanly and accurately; leather doesn't ease or gather like fabric, so inaccurate pieces don't correct themselves.
Sewing
Use a leather needle (wedge-point) in your sewing machine — these cut cleanly through leather rather than tearing through it like a regular needle. Use a longer stitch length than you would for fabric (4–5mm). Don't pin leather — pin holes are permanent. Use binder clips or sewing clips to hold pieces together instead.