To treat a nosebleed effectively, start by ensuring the affected person remains calm. Have them sit upright and lean slightly forward to prevent blood from flowing into the throat. Pinch the soft part of the nose, just below the bridge, and hold it firmly for 10-15 minutes without releasing pressure. Applying a cold compress or ice pack to the bridge of the nose can help constrict blood vessels and slow bleeding. Avoid tilting the head backward, as this may cause blood to flow down the throat. If bleeding persists after 20 minutes of continuous pressure, seek medical attention promptly. Remember, maintaining composure and applying pressure are crucial steps in managing a nosebleed effectively.