How to make a medieval arm bracer.
Something to poke holes in leather with
Step 1: Measuring
You'll want to have a piece of leather big enough to rap around your arm. Measure your arm just above your wrist, just below your elbow, and in between those two spots. You'll then want to mark those measurements down on the side of the leather that will be facing the inside of your arm.
Step 2: Cutting
Cut the piece of leather out, and make sure it fits around your arm well. If it's too big, you can cut it. If it's too small... you can try starting again, or role with it.
Step 3: Hole Punching
Punch holes in the leather. Make sure you use a real tool, and not a pair of scissors or a pencil. This is so that you can make more accurate holes in the places you want. You'll want around six holes on either side, depending on how long your arm is.
Step 4: Lacing
Lace your string into the holes. I use a shoelace, but any string will do, as long as it is strong. Lace it, starting at either end, and lace it like a shoe, all the way to the other end. Then tie the two ends together. Now your done!