Mid Arm:
1. Find the midpoint: With your arm bent at a right angle, locate the midpoint between your shoulder and elbow. You can use a pen to mark the halfway point.
2. Relax your arm: Hang your arm down by your side and relax it.
3. Measure: Place the tape measure around the midpoint of your arm, making sure it's not too tight or too loose. The zero mark should line up with your measurement.