Other than some form of "violence" I don't know. You can try taking blood thinning agents like aspirin in combination with omega-3 fish oils and that might "help". (Assuming you are asking such a question because you WANT your nose to bleed.) Also, being at high(er) elevations can cause a nose to bleed for some reason. That is what I heard anyway. Don't know or care how much truth there is to that.