PK'ing (that, I'm pretty certain you would not like).
My money making is purely outdated, unfortunately, bar 2, which I don't think you'd like. Those two are: dicing (and I mean dice dueling, NOT HOSTING, though) but that is mainly predicated on a 50/50 chance and RS gold you have the capacity to receive cleaned, or make bank (I have cleaned twice, but, since I actually had little money, it didn't actually matter.
PK'ing (that, I'm pretty certain you would not like). By the way, you are able to whip iron dragons fine, it's really not that hard....