I had a lot of nosebleeds when I was growing up. Cauterized a few times. The best way to help prevent them if it's constant or the weather changes use that Vaseline. When it seems to be the same nostril, you might have opened a bigger area/vein and t needs rest... Don't blow your nose too hard.
Worse case was when I woke the morning after spending about an hour in a las Vegas sportsbook. I was choking on my own blood in the morning and rested the rest of the day... Booooo. Very sensitive to smog too... I'll never live in LA.