Ok first things first, when you have one, dont lean back. At work (work at the YMCA teachnig kids how to swim), they always tell our kids tat because people can choke on the blood.
http://susangaer.com/studentprojects/nose.htm
there is proof of it. Best thing to do when you do have one is to lean forward, apply a cold wet paper towel to the top of the nose, to not pinch or touch where the nostrils are. Just let it work its course.
How long do your nose bleeds last for. If they last over 15 minutes and you say you get them often I would recommend checking out a doctor it could be a bleeding issue. I remember when I was young I used to go to bed, wake up and almost always have a nose bleed. Had to get it checked out at the hospital.
Also after you have one, dont blow your nose, or touch it for 24 hours. It taes a very long time for the nose to heal.
like i said, check it out at the doctors to be safe.