Do you want to stop a nose bleed by doing almost nothing?
Here's how... Put some cotton on your upper gums right behind the small dent below your nose,
then press against it hard without hurting yourself.
Most of the nose bleeding comes from a cartilage wall that divides the nose with the upper gum,
so pressing there helps get it to stop in a very short time.
Tip: always relax your muscles to get this done correctly. If the nose bleed doesn't stop, re-position your thumb again and again.
If still fails, try other methods of stopping bleeding like cooling the head with cold water, raising the nose up (gravity) or covering the nose with cotton.