20+ years of experience with nosebleeds here. I've had nose bleeds that have bested Bounty paper towels! (I measured it once, nearly a pint!)
I've seen a ENT doc and after a look in my nose, he noted that I have extensive vasculature near the surface. He recommended either thermal or chemical cauterization. I never got around to making an appointment for that. At the same time, I consulted with a old pharmacist friend (who in contrast to recent pharmacist graduates, actually knows stuff!). He recommended B Complex with C and Zinc. I tried the vitamins and it worked. A little bit of saline nasal spray when I feel dry helps as well. I still get them on occasion, but it's more in response to allergies and irritants, than day-to-day activies.
I just saw the salt pork remedy for nosebleeds yesterday, pretty crazy, never tried it myself. I doubt I'll have to use that one as I never get severe ones anymore.