Omron How to take blood pressure readings?
Taking readings requires some thought and preparation, though it will soon become second nature. There are several things to remember:

Relax. Steer clear of caffeine and exercise for thirty minutes beforehand, and rest for a few minutes. Sit comfortably upright with your feet flat on the floor and with your back supported.
Position your arm correctly. Rest it on a flat surface, with your upper arm level with your heart.
Position the cuff correctly, with the bottom edge just above your elbow.

Sit comfortably in a chair keeping your back straight and your feet flat on the floor. Place the cup on your wrist. Half an inch above your wrist bone. Press the start/stop button on your device