Apart from runecrafting/combat whats best skill to earn money from?

I've been told yews/monks/sharks/cannonball are best for money making, but i'm looking for something that would make atleast 300k to 500k per hour.

 

Merchanting and farming herbs

 

Green Dragon killing, lava dragon killing.

 

farming can be good side money, but hourly ratio is shit TBH.

Said apart from combat >_>

 

what do lava dragons drop out of interest?

you could try mining, seen people make upwards of 80m from just doing say 40-90 mining.

 

They drop lava dragon bones, 07 equivalent of frost bones.
what do you recommend I mine? I'm currently doing nature runes on two accounts for testing they're making about 550 t0 700k on average.